diff --git a/bin/doctrine-dbal.php b/bin/doctrine-dbal.php
index f3e064ffd62..76bed1a6701 100644
--- a/bin/doctrine-dbal.php
+++ b/bin/doctrine-dbal.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use Doctrine\DBAL\Tools\Console\ConsoleRunner;
 use Symfony\Component\Console\Helper\HelperSet;
 
diff --git a/lib/Doctrine/DBAL/Cache/ArrayStatement.php b/lib/Doctrine/DBAL/Cache/ArrayStatement.php
index ef9bf7bff25..cd2984c2b73 100644
--- a/lib/Doctrine/DBAL/Cache/ArrayStatement.php
+++ b/lib/Doctrine/DBAL/Cache/ArrayStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use ArrayIterator;
diff --git a/lib/Doctrine/DBAL/Cache/CacheException.php b/lib/Doctrine/DBAL/Cache/CacheException.php
index 636c948a616..5ad3d3f7aac 100644
--- a/lib/Doctrine/DBAL/Cache/CacheException.php
+++ b/lib/Doctrine/DBAL/Cache/CacheException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php b/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php
index 9433f982fc5..b32fdf6c87e 100644
--- a/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php
+++ b/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use Doctrine\Common\Cache\Cache;
diff --git a/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php b/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php
index 527c730a2fb..49906264885 100644
--- a/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php
+++ b/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use ArrayIterator;
diff --git a/lib/Doctrine/DBAL/ColumnCase.php b/lib/Doctrine/DBAL/ColumnCase.php
index c78ad372e65..0edede03348 100644
--- a/lib/Doctrine/DBAL/ColumnCase.php
+++ b/lib/Doctrine/DBAL/ColumnCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Configuration.php b/lib/Doctrine/DBAL/Configuration.php
index 06b3603ed1e..7cbca89a26a 100644
--- a/lib/Doctrine/DBAL/Configuration.php
+++ b/lib/Doctrine/DBAL/Configuration.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\Common\Cache\Cache;
diff --git a/lib/Doctrine/DBAL/Connection.php b/lib/Doctrine/DBAL/Connection.php
index fe9343b49d6..11fc857b936 100644
--- a/lib/Doctrine/DBAL/Connection.php
+++ b/lib/Doctrine/DBAL/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Closure;
diff --git a/lib/Doctrine/DBAL/ConnectionException.php b/lib/Doctrine/DBAL/ConnectionException.php
index d3d11bc6743..94207b01bd9 100644
--- a/lib/Doctrine/DBAL/ConnectionException.php
+++ b/lib/Doctrine/DBAL/ConnectionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 class ConnectionException extends DBALException
diff --git a/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php b/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php
index 6ef3d034438..3174ed1a17d 100644
--- a/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php
+++ b/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Connections;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/DBALException.php b/lib/Doctrine/DBAL/DBALException.php
index 806e40f59fe..1be382662e6 100644
--- a/lib/Doctrine/DBAL/DBALException.php
+++ b/lib/Doctrine/DBAL/DBALException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Driver\DriverException as DriverExceptionInterface;
diff --git a/lib/Doctrine/DBAL/Driver.php b/lib/Doctrine/DBAL/Driver.php
index dcb03b29492..56a757ce616 100644
--- a/lib/Doctrine/DBAL/Driver.php
+++ b/lib/Doctrine/DBAL/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php b/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php
index c6e0565343a..f283ed163ea 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractDriverException.php b/lib/Doctrine/DBAL/Driver/AbstractDriverException.php
index d9af92d1744..59c08090a4c 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractDriverException.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractDriverException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Exception;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php b/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
index c46ddc63dd7..9229b29bfef 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php b/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php
index dcbaaf097f7..e9e1cce5382 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php b/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php
index bdfd6cd894b..41a9f058e9a 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php b/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php
index f93b576e202..a4c45ccaa23 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php b/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php
index 280f72544e0..dc22ebd5bb1 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php b/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php
index 582f7cae20a..abb7db13153 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/Connection.php b/lib/Doctrine/DBAL/Driver/Connection.php
index 14dbb54f31f..acae0b66f9a 100644
--- a/lib/Doctrine/DBAL/Driver/Connection.php
+++ b/lib/Doctrine/DBAL/Driver/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/DriverException.php b/lib/Doctrine/DBAL/Driver/DriverException.php
index 79480ac72be..c95609712bb 100644
--- a/lib/Doctrine/DBAL/Driver/DriverException.php
+++ b/lib/Doctrine/DBAL/Driver/DriverException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Throwable;
diff --git a/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php b/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php
index 9b79e240c4e..344eca14841 100644
--- a/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php
+++ b/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php
index 4f88decbd69..ef4dd3546d9 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=0);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php
index 43497fd6026..188e08d8caf 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\AbstractDB2Driver;
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php
index cb8e626fcdb..eea9cc1c9e2 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php
index d829c7c79ee..0096feff73c 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php b/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php
index 1166e8d4c2e..52a61293fea 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
index 789b2c8b4ba..0b28b2cae50 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Connection;
@@ -47,7 +49,7 @@ class MysqliConnection implements Connection, PingableConnection, ServerInfoAwar
      */
     public function __construct(array $params, $username, $password, array $driverOptions = [])
     {
-        $port = $params['port'] ?? ini_get('mysqli.default_port');
+        $port = $params['port'] ?? (int) ini_get('mysqli.default_port');
 
         // Fallback to default MySQL port if not given.
         if (! $port) {
@@ -55,9 +57,9 @@ public function __construct(array $params, $username, $password, array $driverOp
         }
 
         $socket = $params['unix_socket'] ?? ini_get('mysqli.default_socket');
-        $dbname = $params['dbname'] ?? null;
+        $dbname = $params['dbname'] ?? '';
 
-        $flags = $driverOptions[static::OPTION_FLAGS] ?? null;
+        $flags = $driverOptions[static::OPTION_FLAGS] ?? 0;
 
         $this->conn = mysqli_init();
 
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php
index 1fa0c900fbd..b779bc40457 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php
index 2faed0afb3c..fed098f3c09 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/Driver.php b/lib/Doctrine/DBAL/Driver/OCI8/Driver.php
index 48195f1517e..4d9341cd580 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php
index 20fb9d4b2e6..8a75d27f62e 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\Connection;
@@ -180,7 +182,7 @@ public function beginTransaction() : void
     public function commit() : void
     {
         if (! oci_commit($this->dbh)) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->dbh));
         }
 
         $this->executeMode = OCI_COMMIT_ON_SUCCESS;
@@ -192,7 +194,7 @@ public function commit() : void
     public function rollBack() : void
     {
         if (! oci_rollback($this->dbh)) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->dbh));
         }
 
         $this->executeMode = OCI_COMMIT_ON_SUCCESS;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php
index af3a9d1a7a9..bdb64347a6a 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php
index 57f14afeb12..00bf3abf36b 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\DBALException;
@@ -296,7 +298,7 @@ public function bindParam($column, &$variable, $type = ParameterType::STRING, $l
             $length ?? -1,
             $this->convertParameterType($type)
         )) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->_sth));
         }
     }
 
@@ -388,7 +390,7 @@ public function execute($params = null) : void
 
         $ret = @oci_execute($this->_sth, $this->_conn->getExecuteMode());
         if (! $ret) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->_sth));
         }
 
         $this->result = true;
diff --git a/lib/Doctrine/DBAL/Driver/PDOConnection.php b/lib/Doctrine/DBAL/Driver/PDOConnection.php
index d9cbb681c8c..bc9128e1eb3 100644
--- a/lib/Doctrine/DBAL/Driver/PDOConnection.php
+++ b/lib/Doctrine/DBAL/Driver/PDOConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use PDO;
diff --git a/lib/Doctrine/DBAL/Driver/PDOException.php b/lib/Doctrine/DBAL/Driver/PDOException.php
index 277d7a62500..47f12e7834c 100644
--- a/lib/Doctrine/DBAL/Driver/PDOException.php
+++ b/lib/Doctrine/DBAL/Driver/PDOException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php b/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php
index 59d27d3844f..0320585573a 100644
--- a/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOMySql;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php b/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php
index f1239eafbd4..79dd059a59f 100644
--- a/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOOracle;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php b/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php
index c3b9e39a026..c081484c666 100644
--- a/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOPgSql;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php b/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php
index c00589101c9..6af349aa721 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlite;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php
index 803ab9e022f..34b7458133d 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\PDOConnection;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php
index 8bc8671620f..2ea7dc2cda7 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\AbstractSQLServerDriver;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php
index 2844a682697..1507c4e45a6 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\PDOStatement;
diff --git a/lib/Doctrine/DBAL/Driver/PDOStatement.php b/lib/Doctrine/DBAL/Driver/PDOStatement.php
index c89507d0e79..b3b252a41f4 100644
--- a/lib/Doctrine/DBAL/Driver/PDOStatement.php
+++ b/lib/Doctrine/DBAL/Driver/PDOStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\DBALException;
@@ -10,6 +12,7 @@
 use const E_USER_DEPRECATED;
 use function array_slice;
 use function assert;
+use function count;
 use function func_get_args;
 use function is_array;
 use function sprintf;
@@ -80,10 +83,15 @@ public function bindValue($param, $value, $type = ParameterType::STRING) : void
      */
     public function bindParam($column, &$variable, $type = ParameterType::STRING, $length = null, $driverOptions = null) : void
     {
-        $type = $this->convertParamType($type);
+        $type            = $this->convertParamType($type);
+        $extraParameters = array_slice(func_get_args(), 3);
+
+        if (count($extraParameters) !== 0) {
+            $extraParameters[0] = $extraParameters[0] ?? 0;
+        }
 
         try {
-            $this->stmt->bindParam($column, $variable, $type, ...array_slice(func_get_args(), 3));
+            $this->stmt->bindParam($column, $variable, $type, ...$extraParameters);
         } catch (\PDOException $exception) {
             throw new PDOException($exception);
         }
diff --git a/lib/Doctrine/DBAL/Driver/PingableConnection.php b/lib/Doctrine/DBAL/Driver/PingableConnection.php
index 06bfb9a7f26..93e6168013e 100644
--- a/lib/Doctrine/DBAL/Driver/PingableConnection.php
+++ b/lib/Doctrine/DBAL/Driver/PingableConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/ResultStatement.php b/lib/Doctrine/DBAL/Driver/ResultStatement.php
index 02422c50177..a00cbf00728 100644
--- a/lib/Doctrine/DBAL/Driver/ResultStatement.php
+++ b/lib/Doctrine/DBAL/Driver/ResultStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Traversable;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php
index 294d5c7a5e9..09a1a8f92fb 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php
index 1ba572dc6e0..d98cffcd9a8 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php
index 0f8bc3e57e6..99e405585e3 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php
index 8b02b9456bb..415be465041 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php b/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php
index a9be26e9dea..287972c74a8 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\AbstractSQLServerDriver;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php b/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php
index 363b260950e..c76e66ff52e 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php
index 7fc1fa0fccc..2e4ac7da767 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php
index 1c1e8c472d7..cbb4fa49e38 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php
index 0cd29288d8f..cb52aa44720 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php b/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php
index c97a60fa356..d17b46c3b74 100644
--- a/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php
+++ b/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/Statement.php b/lib/Doctrine/DBAL/Driver/Statement.php
index dca1ecda43e..8ad231fea10 100644
--- a/lib/Doctrine/DBAL/Driver/Statement.php
+++ b/lib/Doctrine/DBAL/Driver/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Driver/StatementIterator.php b/lib/Doctrine/DBAL/Driver/StatementIterator.php
index 5246b38a448..98d3f08b3a9 100644
--- a/lib/Doctrine/DBAL/Driver/StatementIterator.php
+++ b/lib/Doctrine/DBAL/Driver/StatementIterator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use IteratorAggregate;
diff --git a/lib/Doctrine/DBAL/DriverManager.php b/lib/Doctrine/DBAL/DriverManager.php
index d44b314262e..33cbff22972 100644
--- a/lib/Doctrine/DBAL/DriverManager.php
+++ b/lib/Doctrine/DBAL/DriverManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php b/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php
index bb0ca886d99..8c40a3bfae3 100644
--- a/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\Common\EventArgs;
diff --git a/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php b/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php
index 9e722904050..75fa6c3287f 100644
--- a/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php
+++ b/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event\Listeners;
 
 use Doctrine\Common\EventSubscriber;
diff --git a/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php b/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php
index 19f2b3fd335..413f9c6df16 100644
--- a/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php
+++ b/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event\Listeners;
 
 use Doctrine\Common\EventSubscriber;
diff --git a/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php b/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php
index ea63cab43d7..629e0f43cd8 100644
--- a/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php
+++ b/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event\Listeners;
 
 use Doctrine\Common\EventSubscriber;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php
index 2f9edfea688..9799e9b4e59 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php
index 55661d5d307..33f2fac5fe9 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php
index 8f5f0ecf563..35258004fb9 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php
index 1bc9f590187..80daf00fe07 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php
index 911ea8b4ab6..49f7615c76e 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php
index 19d9f93a329..9e51b1038f0 100644
--- a/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php
index 9d24b8b9049..312892daa7b 100644
--- a/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php
index 954f77aa55a..7c05d1e8df1 100644
--- a/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php
index 387049791d2..9d21bd35e0e 100644
--- a/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaEventArgs.php
index 0db0689c5ad..a5c152872b8 100644
--- a/lib/Doctrine/DBAL/Event/SchemaEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\Common\EventArgs;
diff --git a/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php
index 317f352b87a..bfbd8cfe619 100644
--- a/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Events.php b/lib/Doctrine/DBAL/Events.php
index 5398d0f84c2..605afdb070a 100644
--- a/lib/Doctrine/DBAL/Events.php
+++ b/lib/Doctrine/DBAL/Events.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ConnectionException.php b/lib/Doctrine/DBAL/Exception/ConnectionException.php
index e96a29191e4..4435379b87b 100644
--- a/lib/Doctrine/DBAL/Exception/ConnectionException.php
+++ b/lib/Doctrine/DBAL/Exception/ConnectionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php
index 3959f39af95..7386f7f9a1e 100644
--- a/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php b/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php
index 7e0ba0299e9..e9c52067625 100644
--- a/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php
+++ b/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php b/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php
index 3342bce8d58..ed4107bd26d 100644
--- a/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php
+++ b/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DeadlockException.php b/lib/Doctrine/DBAL/Exception/DeadlockException.php
index fd0550a56b0..5d71a3da95d 100644
--- a/lib/Doctrine/DBAL/Exception/DeadlockException.php
+++ b/lib/Doctrine/DBAL/Exception/DeadlockException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DriverException.php b/lib/Doctrine/DBAL/Exception/DriverException.php
index d3753329882..831ddd08116 100644
--- a/lib/Doctrine/DBAL/Exception/DriverException.php
+++ b/lib/Doctrine/DBAL/Exception/DriverException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php
index 48d736f9e28..166f8503bf9 100644
--- a/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php b/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php
index 5d431e6031d..b0fd74d3591 100644
--- a/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php
+++ b/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php b/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php
index d960feaf869..316414b3e11 100644
--- a/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php
+++ b/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php b/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php
index bfc3a498a3c..4800de5cd7c 100644
--- a/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php
+++ b/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php b/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php
index fd56f89691f..ec2b0baac33 100644
--- a/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php
+++ b/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php
index e327bc94d4d..970be78f0ca 100644
--- a/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ReadOnlyException.php b/lib/Doctrine/DBAL/Exception/ReadOnlyException.php
index a846f2501c8..6def0ac98cb 100644
--- a/lib/Doctrine/DBAL/Exception/ReadOnlyException.php
+++ b/lib/Doctrine/DBAL/Exception/ReadOnlyException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/RetryableException.php b/lib/Doctrine/DBAL/Exception/RetryableException.php
index e1ccd02ffd9..df44635f479 100644
--- a/lib/Doctrine/DBAL/Exception/RetryableException.php
+++ b/lib/Doctrine/DBAL/Exception/RetryableException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ServerException.php b/lib/Doctrine/DBAL/Exception/ServerException.php
index c88c3863b62..ace7c234fdf 100644
--- a/lib/Doctrine/DBAL/Exception/ServerException.php
+++ b/lib/Doctrine/DBAL/Exception/ServerException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php b/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php
index 0b413b71971..893a4ceb49f 100644
--- a/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php
+++ b/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/TableExistsException.php b/lib/Doctrine/DBAL/Exception/TableExistsException.php
index ff0df89afac..bc8ea6e9e20 100644
--- a/lib/Doctrine/DBAL/Exception/TableExistsException.php
+++ b/lib/Doctrine/DBAL/Exception/TableExistsException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/TableNotFoundException.php b/lib/Doctrine/DBAL/Exception/TableNotFoundException.php
index aeaa0057d49..4fe86396942 100644
--- a/lib/Doctrine/DBAL/Exception/TableNotFoundException.php
+++ b/lib/Doctrine/DBAL/Exception/TableNotFoundException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php
index c762ad3c78a..0d51a721a54 100644
--- a/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/FetchMode.php b/lib/Doctrine/DBAL/FetchMode.php
index 65af014f1e0..ad0d22e6738 100644
--- a/lib/Doctrine/DBAL/FetchMode.php
+++ b/lib/Doctrine/DBAL/FetchMode.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Id/TableGenerator.php b/lib/Doctrine/DBAL/Id/TableGenerator.php
index cb34dcd5c4b..ad4770598e4 100644
--- a/lib/Doctrine/DBAL/Id/TableGenerator.php
+++ b/lib/Doctrine/DBAL/Id/TableGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Id;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php b/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php
index 3ec22f37c5c..9e2efa91b46 100644
--- a/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php
+++ b/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Id;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/LockMode.php b/lib/Doctrine/DBAL/LockMode.php
index 14e81432b43..9c2f901d87c 100644
--- a/lib/Doctrine/DBAL/LockMode.php
+++ b/lib/Doctrine/DBAL/LockMode.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Logging/DebugStack.php b/lib/Doctrine/DBAL/Logging/DebugStack.php
index bd1358f321d..2cd85a8e35f 100644
--- a/lib/Doctrine/DBAL/Logging/DebugStack.php
+++ b/lib/Doctrine/DBAL/Logging/DebugStack.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 use function microtime;
diff --git a/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php b/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php
index cfca9dd7c90..754b34269d7 100644
--- a/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php
+++ b/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 use const PHP_EOL;
diff --git a/lib/Doctrine/DBAL/Logging/LoggerChain.php b/lib/Doctrine/DBAL/Logging/LoggerChain.php
index 226faae83da..ca47c566e2e 100644
--- a/lib/Doctrine/DBAL/Logging/LoggerChain.php
+++ b/lib/Doctrine/DBAL/Logging/LoggerChain.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 /**
diff --git a/lib/Doctrine/DBAL/Logging/NullLogger.php b/lib/Doctrine/DBAL/Logging/NullLogger.php
index b0ffb53c817..6269b6f610c 100644
--- a/lib/Doctrine/DBAL/Logging/NullLogger.php
+++ b/lib/Doctrine/DBAL/Logging/NullLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 /**
diff --git a/lib/Doctrine/DBAL/Logging/SQLLogger.php b/lib/Doctrine/DBAL/Logging/SQLLogger.php
index 99aa494426b..10d5b35823c 100644
--- a/lib/Doctrine/DBAL/Logging/SQLLogger.php
+++ b/lib/Doctrine/DBAL/Logging/SQLLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 /**
diff --git a/lib/Doctrine/DBAL/ParameterType.php b/lib/Doctrine/DBAL/ParameterType.php
index 022b2703ef5..b392ddbe95a 100644
--- a/lib/Doctrine/DBAL/ParameterType.php
+++ b/lib/Doctrine/DBAL/ParameterType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php b/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php
index 739d3ca6930..e4470b07bb3 100644
--- a/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/Platforms/DB2Platform.php b/lib/Doctrine/DBAL/Platforms/DB2Platform.php
index b90380ddbb5..b9fc54cf5f4 100644
--- a/lib/Doctrine/DBAL/Platforms/DB2Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/DB2Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php
index db577d30207..1327ffbeee2 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php b/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php
index 860d9f21099..251722313ff 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_flip;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php
index 1b31c7682e7..010f694232a 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php
index 9b60a3f1c54..eda315f58cd 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php
index 4b595d53a08..566a55552a6 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_merge;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php
index 84ca1446a8b..9ec94c2df61 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php
index a73a93d60c0..c134693a6ba 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php
index 7bf29cd2aa5..421819544f3 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_diff;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php
index 92b45609cc0..017b4e02f63 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php b/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php
index 68cdf3d15d8..4aab336d10e 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php
index dc60610738b..f7b6b0bd2a5 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php
index d29225270aa..df64901862a 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_merge;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php
index e43bde2fe5c..b72e7342e3b 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php
index a0c9c797ef9..22c92d72f11 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php b/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php
index 25420a0476e..548eafcea53 100644
--- a/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Types\Type;
diff --git a/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php b/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php
index 71ef6ca96c7..8af3bf582c7 100644
--- a/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Index;
diff --git a/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php b/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php
index f6d4be9dc4c..7e07dc9dbb7 100644
--- a/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php b/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php
index 78e318df264..d8fb568bf1b 100644
--- a/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Platforms/OraclePlatform.php b/lib/Doctrine/DBAL/Platforms/OraclePlatform.php
index c463f722e5e..63f7442786c 100644
--- a/lib/Doctrine/DBAL/Platforms/OraclePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/OraclePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php b/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php
index 8cb65542e3b..92f921a5ddd 100644
--- a/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Types\Type;
diff --git a/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php b/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php
index 3b5d46648e6..4fa61fbdeca 100644
--- a/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Column;
@@ -901,7 +903,7 @@ static function ($boolean) {
      */
     public function convertFromBoolean($item)
     {
-        if (in_array(strtolower($item), $this->booleanLiterals['false'], true)) {
+        if (in_array($item, $this->booleanLiterals['false'], true)) {
             return false;
         }
 
diff --git a/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php b/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php
index 36714143b85..691d72ea908 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php b/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php
index c95d93c9a86..72e2acfa31b 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php b/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php
index afc6a32b060..8066a772ae5 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Sequence;
diff --git a/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php b/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php
index d385f334f8d..1c269628ac0 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\LockMode;
diff --git a/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php b/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php
index f2842f8e16a..a8630569e6d 100644
--- a/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Portability/Connection.php b/lib/Doctrine/DBAL/Portability/Connection.php
index 5194b66a611..8c64822f9e0 100644
--- a/lib/Doctrine/DBAL/Portability/Connection.php
+++ b/lib/Doctrine/DBAL/Portability/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Portability;
 
 use Doctrine\DBAL\Cache\QueryCacheProfile;
diff --git a/lib/Doctrine/DBAL/Portability/Statement.php b/lib/Doctrine/DBAL/Portability/Statement.php
index 7e9edfeadb3..c2ab9534fd7 100644
--- a/lib/Doctrine/DBAL/Portability/Statement.php
+++ b/lib/Doctrine/DBAL/Portability/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Portability;
 
 use Doctrine\DBAL\Driver\ResultStatement;
diff --git a/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php b/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php
index 443d71bc37e..93600f0ffb4 100644
--- a/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php
+++ b/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query\Expression;
 
 use Countable;
diff --git a/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php b/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php
index 93cbd31e95f..573df7b60b0 100644
--- a/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php
+++ b/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query\Expression;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Query/QueryBuilder.php b/lib/Doctrine/DBAL/Query/QueryBuilder.php
index a400d1d5dcb..7af89326acf 100644
--- a/lib/Doctrine/DBAL/Query/QueryBuilder.php
+++ b/lib/Doctrine/DBAL/Query/QueryBuilder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Query/QueryException.php b/lib/Doctrine/DBAL/Query/QueryException.php
index 3fcb3b480ec..b692557051d 100644
--- a/lib/Doctrine/DBAL/Query/QueryException.php
+++ b/lib/Doctrine/DBAL/Query/QueryException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/SQLParserUtils.php b/lib/Doctrine/DBAL/SQLParserUtils.php
index 0ff0456a00e..279dded3799 100644
--- a/lib/Doctrine/DBAL/SQLParserUtils.php
+++ b/lib/Doctrine/DBAL/SQLParserUtils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use const PREG_OFFSET_CAPTURE;
diff --git a/lib/Doctrine/DBAL/SQLParserUtilsException.php b/lib/Doctrine/DBAL/SQLParserUtilsException.php
index a500ed52dd3..e2d8bbac65d 100644
--- a/lib/Doctrine/DBAL/SQLParserUtilsException.php
+++ b/lib/Doctrine/DBAL/SQLParserUtilsException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use function sprintf;
diff --git a/lib/Doctrine/DBAL/Schema/AbstractAsset.php b/lib/Doctrine/DBAL/Schema/AbstractAsset.php
index 45af02f5cc9..cfa469d9de7 100644
--- a/lib/Doctrine/DBAL/Schema/AbstractAsset.php
+++ b/lib/Doctrine/DBAL/Schema/AbstractAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -166,7 +168,7 @@ public function getName()
             return $this->_namespace . '.' . $this->_name;
         }
 
-        return $this->_name;
+        return $this->_name ?? '';
     }
 
     /**
diff --git a/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php b/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php
index 46fbff6da30..a3edcdb2206 100644
--- a/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Schema/Column.php b/lib/Doctrine/DBAL/Schema/Column.php
index 56c39c14994..5c21b708aaa 100644
--- a/lib/Doctrine/DBAL/Schema/Column.php
+++ b/lib/Doctrine/DBAL/Schema/Column.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Types\Type;
diff --git a/lib/Doctrine/DBAL/Schema/ColumnDiff.php b/lib/Doctrine/DBAL/Schema/ColumnDiff.php
index 1589f98d4a9..f98f9108bfd 100644
--- a/lib/Doctrine/DBAL/Schema/ColumnDiff.php
+++ b/lib/Doctrine/DBAL/Schema/ColumnDiff.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use function in_array;
diff --git a/lib/Doctrine/DBAL/Schema/Comparator.php b/lib/Doctrine/DBAL/Schema/Comparator.php
index 84d7808abef..c4d3064e9d3 100644
--- a/lib/Doctrine/DBAL/Schema/Comparator.php
+++ b/lib/Doctrine/DBAL/Schema/Comparator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Types;
diff --git a/lib/Doctrine/DBAL/Schema/Constraint.php b/lib/Doctrine/DBAL/Schema/Constraint.php
index 65e239ec119..c939a06e33e 100644
--- a/lib/Doctrine/DBAL/Schema/Constraint.php
+++ b/lib/Doctrine/DBAL/Schema/Constraint.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php b/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php
index ba6048a092b..fb412019fc4 100644
--- a/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Types\Type;
diff --git a/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php b/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php
index 3c6585e4600..3ccd2ede590 100644
--- a/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php
+++ b/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -90,7 +92,7 @@ private function createIdentifierMap(array $names) : array
         $identifiers = [];
 
         foreach ($names as $name) {
-            $identifiers[$name] = new Identifier($name);
+            $identifiers[$name] = new Identifier($name ?? '');
         }
 
         return $identifiers;
diff --git a/lib/Doctrine/DBAL/Schema/Identifier.php b/lib/Doctrine/DBAL/Schema/Identifier.php
index f34465e9efb..276b7824f1a 100644
--- a/lib/Doctrine/DBAL/Schema/Identifier.php
+++ b/lib/Doctrine/DBAL/Schema/Identifier.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/Index.php b/lib/Doctrine/DBAL/Schema/Index.php
index 18a26b8d306..b895f3e14a8 100644
--- a/lib/Doctrine/DBAL/Schema/Index.php
+++ b/lib/Doctrine/DBAL/Schema/Index.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -57,7 +59,9 @@ public function __construct($indexName, array $columns, $isUnique = false, $isPr
     {
         $isUnique = $isUnique || $isPrimary;
 
-        $this->_setName($indexName);
+        if ($indexName !== null) {
+            $this->_setName($indexName);
+        }
 
         $this->_isUnique  = $isUnique;
         $this->_isPrimary = $isPrimary;
diff --git a/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php b/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php
index b39db01ffaa..ba140a6b4d7 100644
--- a/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\MariaDb1027Platform;
diff --git a/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php b/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php
index cabc94b1867..8acabf36642 100644
--- a/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
@@ -98,7 +100,7 @@ protected function _getPortableTableIndexesList(array $tableIndexRows, string $t
             $keyName = strtolower($tableIndex['name']);
             $buffer  = [];
 
-            if (strtolower($tableIndex['is_primary']) === 'p') {
+            if ($tableIndex['is_primary'] === 'P') {
                 $keyName              = 'primary';
                 $buffer['primary']    = true;
                 $buffer['non_unique'] = false;
@@ -137,7 +139,9 @@ protected function _getPortableTableColumnDefinition($tableColumn)
         }
 
         // Default values returned from database sometimes have trailing spaces.
-        $tableColumn['data_default'] = trim($tableColumn['data_default']);
+        if ($tableColumn['data_default'] !== null) {
+            $tableColumn['data_default'] = trim($tableColumn['data_default']);
+        }
 
         if ($tableColumn['data_default'] === '' || $tableColumn['data_default'] === 'NULL') {
             $tableColumn['data_default'] = null;
diff --git a/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php b/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php
index 43a4d27ae35..ba47929e888 100644
--- a/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Exception\DriverException;
@@ -323,17 +325,17 @@ protected function _getPortableTableColumnDefinition($tableColumn)
         $matches = [];
 
         $autoincrement = false;
-        if (preg_match("/^nextval\('(.*)'(::.*)?\)$/", $tableColumn['default'], $matches)) {
+        if ($tableColumn['default'] !== null && preg_match("/^nextval\('(.*)'(::.*)?\)$/", $tableColumn['default'], $matches)) {
             $tableColumn['sequence'] = $matches[1];
             $tableColumn['default']  = null;
             $autoincrement           = true;
         }
 
-        if (preg_match("/^['(](.*)[')]::.*$/", $tableColumn['default'], $matches)) {
+        if ($tableColumn['default'] !== null && preg_match("/^['(](.*)[')]::.*$/", $tableColumn['default'], $matches)) {
             $tableColumn['default'] = $matches[1];
         }
 
-        if (stripos($tableColumn['default'], 'NULL') === 0) {
+        if ($tableColumn['default'] !== null && stripos($tableColumn['default'], 'NULL') === 0) {
             $tableColumn['default'] = null;
         }
 
@@ -355,7 +357,10 @@ protected function _getPortableTableColumnDefinition($tableColumn)
         $jsonb     = null;
 
         $dbType = strtolower($tableColumn['type']);
-        if (strlen($tableColumn['domain_type']) && ! $this->_platform->hasDoctrineTypeMappingFor($tableColumn['type'])) {
+        if ($tableColumn['domain_type'] !== null
+            && strlen($tableColumn['domain_type'])
+            && ! $this->_platform->hasDoctrineTypeMappingFor($tableColumn['type'])
+        ) {
             $dbType                       = strtolower($tableColumn['domain_type']);
             $tableColumn['complete_type'] = $tableColumn['domain_complete_type'];
         }
@@ -472,7 +477,7 @@ protected function _getPortableTableColumnDefinition($tableColumn)
      */
     private function fixVersion94NegativeNumericDefaultValue($defaultValue)
     {
-        if (strpos($defaultValue, '(') === 0) {
+        if ($defaultValue !== null && strpos($defaultValue, '(') === 0) {
             return trim($defaultValue, '()');
         }
 
diff --git a/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php b/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php
index 0d875491167..b99d68429e0 100644
--- a/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\SQLAnywherePlatform;
diff --git a/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php b/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php
index 757136418bd..127f8587e01 100644
--- a/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/Schema.php b/lib/Doctrine/DBAL/Schema/Schema.php
index 5d746654a40..fa7e2472e15 100644
--- a/lib/Doctrine/DBAL/Schema/Schema.php
+++ b/lib/Doctrine/DBAL/Schema/Schema.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/SchemaConfig.php b/lib/Doctrine/DBAL/Schema/SchemaConfig.php
index b8c3502f758..e3a2f36b0b4 100644
--- a/lib/Doctrine/DBAL/Schema/SchemaConfig.php
+++ b/lib/Doctrine/DBAL/Schema/SchemaConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/SchemaDiff.php b/lib/Doctrine/DBAL/Schema/SchemaDiff.php
index 69bf125a844..97033eeeebb 100644
--- a/lib/Doctrine/DBAL/Schema/SchemaDiff.php
+++ b/lib/Doctrine/DBAL/Schema/SchemaDiff.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/SchemaException.php b/lib/Doctrine/DBAL/Schema/SchemaException.php
index 658663ac16a..1271e9db0a6 100644
--- a/lib/Doctrine/DBAL/Schema/SchemaException.php
+++ b/lib/Doctrine/DBAL/Schema/SchemaException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/Sequence.php b/lib/Doctrine/DBAL/Schema/Sequence.php
index 88891019bfd..89147984136 100644
--- a/lib/Doctrine/DBAL/Schema/Sequence.php
+++ b/lib/Doctrine/DBAL/Schema/Sequence.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Visitor\Visitor;
diff --git a/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php b/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php
index 5e03342e482..c975fb1783b 100644
--- a/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php b/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php
index b597b8db9b2..74dce854098 100644
--- a/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php
+++ b/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php b/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php
index 3e7beea7508..8e0eb117c4f 100644
--- a/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php
+++ b/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Schema\Schema;
diff --git a/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php b/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php
index dd4b1ca5f40..83abc250596 100644
--- a/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php
+++ b/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Schema/Table.php b/lib/Doctrine/DBAL/Schema/Table.php
index 781df0ed27a..855f2a457e9 100644
--- a/lib/Doctrine/DBAL/Schema/Table.php
+++ b/lib/Doctrine/DBAL/Schema/Table.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/TableDiff.php b/lib/Doctrine/DBAL/Schema/TableDiff.php
index 1ff2c0ad105..bdbce7da3b3 100644
--- a/lib/Doctrine/DBAL/Schema/TableDiff.php
+++ b/lib/Doctrine/DBAL/Schema/TableDiff.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/UniqueConstraint.php b/lib/Doctrine/DBAL/Schema/UniqueConstraint.php
index 8d47424769c..44f0f5cd150 100644
--- a/lib/Doctrine/DBAL/Schema/UniqueConstraint.php
+++ b/lib/Doctrine/DBAL/Schema/UniqueConstraint.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/View.php b/lib/Doctrine/DBAL/Schema/View.php
index ac8d6cb5cb4..18ca8664c9e 100644
--- a/lib/Doctrine/DBAL/Schema/View.php
+++ b/lib/Doctrine/DBAL/Schema/View.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php b/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php
index 47169044274..318ba1f1126 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php b/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php
index cc15bc0f655..cea93eeb4f1 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php b/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php
index 81e2023128b..6e6b1e62f2e 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php b/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php
index 06e8413c8a4..96aa180133a 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php b/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php
index 186fe1b4213..fd09ff7cdab 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php b/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php
index 001ea2a0d70..196e43e46c3 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php b/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php
index 5ec843d9be6..358ddf7d777 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php b/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php
index 05c842830c5..3d80991c4d9 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php b/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php
index 649a4e256fe..99e015b176e 100644
--- a/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php
+++ b/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php b/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
index 5edc56b8778..d0efce31ab2 100644
--- a/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 use Doctrine\DBAL\Sharding\ShardChoser\ShardChoser;
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
index 32d642365b0..bd2f7af7417 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\SQLAzure;
 
 use Closure;
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
index 11bd965c158..40fb9db3bd6 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
index a83b401c2cd..dd35e119a57 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\SQLAzure\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php b/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php
index 584e8155ae9..c6c2f3843f4 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\ShardChoser;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php b/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php
index 6f8a9d47702..57c247aa65b 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\ShardChoser;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/lib/Doctrine/DBAL/Sharding/ShardManager.php b/lib/Doctrine/DBAL/Sharding/ShardManager.php
index 7b37bb2c7e1..793b0bb9340 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 /**
diff --git a/lib/Doctrine/DBAL/Sharding/ShardingException.php b/lib/Doctrine/DBAL/Sharding/ShardingException.php
index b46bda2ff0d..3e6c91c3844 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardingException.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardingException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Statement.php b/lib/Doctrine/DBAL/Statement.php
index fc6608fb3d2..7022c809b61 100644
--- a/lib/Doctrine/DBAL/Statement.php
+++ b/lib/Doctrine/DBAL/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Driver\DriverException;
diff --git a/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php b/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php
index a8020a15399..020e9b2164f 100644
--- a/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php
+++ b/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console\Command;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php b/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php
index 8aeb0ea2fba..2a55fb6df36 100644
--- a/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php
+++ b/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console\Command;
 
 use Doctrine\DBAL\Tools\Dumper;
diff --git a/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php b/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php
index 0df6f086f2c..32a00549c77 100644
--- a/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php
+++ b/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php b/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php
index b5497d068a0..836bd8d8568 100644
--- a/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php
+++ b/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console\Helper;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Tools/Dumper.php b/lib/Doctrine/DBAL/Tools/Dumper.php
index 3668efbe4d1..36f44555414 100644
--- a/lib/Doctrine/DBAL/Tools/Dumper.php
+++ b/lib/Doctrine/DBAL/Tools/Dumper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools;
 
 use ArrayIterator;
@@ -58,11 +60,11 @@ public static function dump($var, int $maxDepth = 2) : string
         $html = ini_get('html_errors');
 
         if ($html !== true) {
-            ini_set('html_errors', true);
+            ini_set('html_errors', '1');
         }
 
         if (extension_loaded('xdebug')) {
-            ini_set('xdebug.var_display_max_depth', $maxDepth);
+            ini_set('xdebug.var_display_max_depth', (string) $maxDepth);
         }
 
         $var = self::export($var, $maxDepth);
@@ -149,7 +151,7 @@ private static function fillReturnWithClassAttributes($var, stdClass $return, in
         $clone = (array) $var;
 
         foreach (array_keys($clone) as $key) {
-            $aux  = explode("\0", $key);
+            $aux  = explode("\0", (string) $key);
             $name = end($aux);
             if ($aux[0] === '') {
                 $name .= ':' . ($aux[1] === '*' ? 'protected' : $aux[1] . ':private');
diff --git a/lib/Doctrine/DBAL/Types/ArrayType.php b/lib/Doctrine/DBAL/Types/ArrayType.php
index 9bb8e578b23..5281f85f661 100644
--- a/lib/Doctrine/DBAL/Types/ArrayType.php
+++ b/lib/Doctrine/DBAL/Types/ArrayType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/BigIntType.php b/lib/Doctrine/DBAL/Types/BigIntType.php
index 1d320d624d4..9a9ddeccf68 100644
--- a/lib/Doctrine/DBAL/Types/BigIntType.php
+++ b/lib/Doctrine/DBAL/Types/BigIntType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/BinaryType.php b/lib/Doctrine/DBAL/Types/BinaryType.php
index e40f0010493..545ebbbfb37 100644
--- a/lib/Doctrine/DBAL/Types/BinaryType.php
+++ b/lib/Doctrine/DBAL/Types/BinaryType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/BlobType.php b/lib/Doctrine/DBAL/Types/BlobType.php
index c9c8d88ec1c..e699dba9624 100644
--- a/lib/Doctrine/DBAL/Types/BlobType.php
+++ b/lib/Doctrine/DBAL/Types/BlobType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/BooleanType.php b/lib/Doctrine/DBAL/Types/BooleanType.php
index 976f00e1fb7..d14911f2086 100644
--- a/lib/Doctrine/DBAL/Types/BooleanType.php
+++ b/lib/Doctrine/DBAL/Types/BooleanType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/ConversionException.php b/lib/Doctrine/DBAL/Types/ConversionException.php
index b9f8a82e7ec..325c8c2d3f8 100644
--- a/lib/Doctrine/DBAL/Types/ConversionException.php
+++ b/lib/Doctrine/DBAL/Types/ConversionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\DBALException;
@@ -9,6 +11,7 @@
 use function implode;
 use function is_object;
 use function is_scalar;
+use function is_string;
 use function sprintf;
 use function strlen;
 use function substr;
@@ -21,14 +24,14 @@ class ConversionException extends DBALException
     /**
      * Thrown when a Database to Doctrine Type Conversion fails.
      *
-     * @param string $value
+     * @param mixed  $value
      * @param string $toType
      *
      * @return \Doctrine\DBAL\Types\ConversionException
      */
     public static function conversionFailed($value, $toType)
     {
-        $value = strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
+        $value = is_string($value) && strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
 
         return new self('Could not convert database value "' . $value . '" to Doctrine Type ' . $toType);
     }
@@ -37,7 +40,7 @@ public static function conversionFailed($value, $toType)
      * Thrown when a Database to Doctrine Type Conversion fails and we can make a statement
      * about the expected format.
      *
-     * @param string $value
+     * @param mixed  $value
      * @param string $toType
      * @param string $expectedFormat
      *
@@ -45,7 +48,7 @@ public static function conversionFailed($value, $toType)
      */
     public static function conversionFailedFormat($value, $toType, $expectedFormat, ?Throwable $previous = null)
     {
-        $value = strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
+        $value = is_string($value) && strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
 
         return new self(
             'Could not convert database value "' . $value . '" to Doctrine Type ' .
diff --git a/lib/Doctrine/DBAL/Types/DateImmutableType.php b/lib/Doctrine/DBAL/Types/DateImmutableType.php
index 196fc88c7b4..66648417a3c 100644
--- a/lib/Doctrine/DBAL/Types/DateImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/DateImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/DateIntervalType.php b/lib/Doctrine/DBAL/Types/DateIntervalType.php
index 30e61c9eaa5..aacf7527c14 100644
--- a/lib/Doctrine/DBAL/Types/DateIntervalType.php
+++ b/lib/Doctrine/DBAL/Types/DateIntervalType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateInterval;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php b/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php
index fdda50faa44..b8d81638ea6 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeType.php b/lib/Doctrine/DBAL/Types/DateTimeType.php
index 962d9d38da0..b0eb9c1e8dd 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php b/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php
index 253c02e002b..6000983f034 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeTzType.php b/lib/Doctrine/DBAL/Types/DateTimeTzType.php
index 0b78720ec3e..1fe6da887f1 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeTzType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeTzType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/DateType.php b/lib/Doctrine/DBAL/Types/DateType.php
index b5ad5356f69..a16b5bcd0cd 100644
--- a/lib/Doctrine/DBAL/Types/DateType.php
+++ b/lib/Doctrine/DBAL/Types/DateType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/DecimalType.php b/lib/Doctrine/DBAL/Types/DecimalType.php
index 318cb2476b7..fd042ee09bc 100644
--- a/lib/Doctrine/DBAL/Types/DecimalType.php
+++ b/lib/Doctrine/DBAL/Types/DecimalType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/FloatType.php b/lib/Doctrine/DBAL/Types/FloatType.php
index 3ad9aa737fa..0f72404a522 100644
--- a/lib/Doctrine/DBAL/Types/FloatType.php
+++ b/lib/Doctrine/DBAL/Types/FloatType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/GuidType.php b/lib/Doctrine/DBAL/Types/GuidType.php
index a9ab21537c5..79fec56c103 100644
--- a/lib/Doctrine/DBAL/Types/GuidType.php
+++ b/lib/Doctrine/DBAL/Types/GuidType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/IntegerType.php b/lib/Doctrine/DBAL/Types/IntegerType.php
index f04f3c7e008..b8f90a0a837 100644
--- a/lib/Doctrine/DBAL/Types/IntegerType.php
+++ b/lib/Doctrine/DBAL/Types/IntegerType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/JsonArrayType.php b/lib/Doctrine/DBAL/Types/JsonArrayType.php
index beae8038737..9f6cd382927 100644
--- a/lib/Doctrine/DBAL/Types/JsonArrayType.php
+++ b/lib/Doctrine/DBAL/Types/JsonArrayType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/JsonType.php b/lib/Doctrine/DBAL/Types/JsonType.php
index 00cd3f80fcf..2c7c2110b1f 100644
--- a/lib/Doctrine/DBAL/Types/JsonType.php
+++ b/lib/Doctrine/DBAL/Types/JsonType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/ObjectType.php b/lib/Doctrine/DBAL/Types/ObjectType.php
index 081ec483b16..9240b381f5a 100644
--- a/lib/Doctrine/DBAL/Types/ObjectType.php
+++ b/lib/Doctrine/DBAL/Types/ObjectType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php b/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php
index 45658505330..501bc37a7be 100644
--- a/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php
+++ b/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 /**
diff --git a/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php b/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php
index b48e29c865a..d2b208478d1 100644
--- a/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php
+++ b/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 /**
diff --git a/lib/Doctrine/DBAL/Types/SimpleArrayType.php b/lib/Doctrine/DBAL/Types/SimpleArrayType.php
index d23776f5f0a..7b1a9f64796 100644
--- a/lib/Doctrine/DBAL/Types/SimpleArrayType.php
+++ b/lib/Doctrine/DBAL/Types/SimpleArrayType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/SmallIntType.php b/lib/Doctrine/DBAL/Types/SmallIntType.php
index bca8a533f06..8798c949029 100644
--- a/lib/Doctrine/DBAL/Types/SmallIntType.php
+++ b/lib/Doctrine/DBAL/Types/SmallIntType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/StringType.php b/lib/Doctrine/DBAL/Types/StringType.php
index c6197df949a..3bad5259e50 100644
--- a/lib/Doctrine/DBAL/Types/StringType.php
+++ b/lib/Doctrine/DBAL/Types/StringType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/TextType.php b/lib/Doctrine/DBAL/Types/TextType.php
index 635d4f7de49..f9b4e98106b 100644
--- a/lib/Doctrine/DBAL/Types/TextType.php
+++ b/lib/Doctrine/DBAL/Types/TextType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/TimeImmutableType.php b/lib/Doctrine/DBAL/Types/TimeImmutableType.php
index 8cb870fb393..901a2217c94 100644
--- a/lib/Doctrine/DBAL/Types/TimeImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/TimeImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/TimeType.php b/lib/Doctrine/DBAL/Types/TimeType.php
index c9895294e03..2bdccf8e3c4 100644
--- a/lib/Doctrine/DBAL/Types/TimeType.php
+++ b/lib/Doctrine/DBAL/Types/TimeType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/Type.php b/lib/Doctrine/DBAL/Types/Type.php
index 6cee27cedab..4e632428bfa 100644
--- a/lib/Doctrine/DBAL/Types/Type.php
+++ b/lib/Doctrine/DBAL/Types/Type.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php b/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php
index 6636f53a5b2..86440c53662 100644
--- a/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/VarDateTimeType.php b/lib/Doctrine/DBAL/Types/VarDateTimeType.php
index 1d9dbd3a6c6..fe431da91e8 100644
--- a/lib/Doctrine/DBAL/Types/VarDateTimeType.php
+++ b/lib/Doctrine/DBAL/Types/VarDateTimeType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php b/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php
index a4864d0b287..c61f47d2df0 100644
--- a/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php
+++ b/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 6fdaaf512c4..a469f0b70e4 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -14,7 +14,6 @@
     <file>tests</file>
 
     <rule ref="Doctrine">
-        <exclude name="SlevomatCodingStandard.TypeHints.DeclareStrictTypes"/>
         <exclude name="SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingParameterTypeHint"/>
         <exclude name="SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingReturnTypeHint"/>
         <exclude name="SlevomatCodingStandard.Classes.SuperfluousAbstractClassNaming"/>
@@ -65,4 +64,10 @@
     <rule ref="SlevomatCodingStandard.Operators.DisallowEqualOperators.DisallowedNotEqualOperator">
         <exclude-pattern>lib/Doctrine/DBAL/Schema/Comparator.php</exclude-pattern>
     </rule>
+
+    <!-- DB2_AUTOCOMMIT_ON/DB2_AUTOCOMMIT_OFF are of int type but db2_autocommit() incorrectly expects bool,
+         see https://bugs.php.net/bug.php?id=77591 -->
+    <rule ref="SlevomatCodingStandard.TypeHints.DeclareStrictTypes.DeclareStrictTypesMissing">
+        <exclude-pattern>lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php</exclude-pattern>
+    </rule>
 </ruleset>
diff --git a/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php b/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php
index 2a8fe528c9d..6722f68c372 100644
--- a/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php
+++ b/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Cache;
 
 use Doctrine\DBAL\Cache\QueryCacheProfile;
diff --git a/tests/Doctrine/Tests/DBAL/ConfigurationTest.php b/tests/Doctrine/Tests/DBAL/ConfigurationTest.php
index 87189bec852..4b8d9f1990f 100644
--- a/tests/Doctrine/Tests/DBAL/ConfigurationTest.php
+++ b/tests/Doctrine/Tests/DBAL/ConfigurationTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Configuration;
diff --git a/tests/Doctrine/Tests/DBAL/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/ConnectionTest.php
index c47e9fc1ce9..004dfbb288a 100644
--- a/tests/Doctrine/Tests/DBAL/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\Common\Cache\Cache;
diff --git a/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php b/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php
index ccd1becfac9..e3aeead3e27 100644
--- a/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php
index e6a54060c71..efed41f35f8 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php
index 6a16dd65a91..47d04e03373 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
@@ -269,7 +271,7 @@ private function getExceptionConversions()
 
                     public function __construct($errorCode, $sqlState, $message)
                     {
-                        parent::__construct($message);
+                        parent::__construct($message ?? '');
 
                         $this->errorCode = $errorCode;
                         $this->sqlState  = $sqlState;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php
index cde381653a9..81140b97754 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php
index efb250d1ac7..e53b7ae695f 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\AbstractOracleDriver;
 
 use Doctrine\DBAL\Driver\AbstractOracleDriver\EasyConnectString;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php
index d88040e10a7..fcf5bd6366e 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php
index c51617bafc4..f7f06b1423e 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php
index a05fef71214..f3bdb4ebb23 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php
index 69eea132855..2afeabfad8f 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php
index d92aa5d0d8d..a53229cd5b7 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php
index b6b32751262..8a25b18fef9 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\IBMDB2\DB2Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php
index 93f390b628a..07c80865902 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\IBMDB2\DB2Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php
index f38ff8a5529..657944bd266 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Mysqli\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php
index 52dc12eb693..bab55bbbc69 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Mysqli\MysqliConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php
index 77e763a66bb..f6b6ed25405 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php
index 81466a3a72e..3a9e639e1d9 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\OCI8Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php
index ec2e69a8f6d..c0904d01797 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\OCI8Connection;
@@ -7,7 +9,9 @@
 use Doctrine\DBAL\Driver\OCI8\OCI8Statement;
 use Doctrine\Tests\DbalTestCase;
 use ReflectionProperty;
+use const OCI_NO_AUTO_COMMIT;
 use function extension_loaded;
+use function fopen;
 
 class OCI8StatementTest extends DbalTestCase
 {
@@ -57,11 +61,16 @@ public function testExecute(array $params)
             ->disableOriginalConstructor()
             ->getMock();
         $conn->expects($this->once())
-            ->method('getExecuteMode');
+            ->method('getExecuteMode')
+            ->willReturn(OCI_NO_AUTO_COMMIT);
+
+        $connectionReflection = new ReflectionProperty($statement, '_conn');
+        $connectionReflection->setAccessible(true);
+        $connectionReflection->setValue($statement, $conn);
 
-        $reflProperty = new ReflectionProperty($statement, '_conn');
-        $reflProperty->setAccessible(true);
-        $reflProperty->setValue($statement, $conn);
+        $handleReflection = new ReflectionProperty($statement, '_sth');
+        $handleReflection->setAccessible(true);
+        $handleReflection->setValue($statement, fopen('php://temp', 'r'));
 
         $this->expectException(OCI8Exception::class);
         $statement->execute($params);
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php
index c7564470252..08b69ee253d 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Driver\PDOException;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php
index a965765780d..8e9273d476c 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOMySql;
 
 use Doctrine\DBAL\Driver\PDOMySql\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php
index f9e0da70f1c..a322c116409 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOOracle;
 
 use Doctrine\DBAL\Driver\PDOOracle\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php
index 1e3a2745b65..00d75b90cb0 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOPgSql;
 
 use Doctrine\DBAL\Driver\PDOConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php
index 49a604ccd07..5bbc56021c0 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOSqlite;
 
 use Doctrine\DBAL\Driver\PDOSqlite\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php
index bf060365838..ef308d8d1d7 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\PDOSqlsrv\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php
index 54b1912a911..5325a97a599 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\SQLAnywhere\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php
index ccf6e3358f2..3de5447aaf8 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\SQLAnywhere\SQLAnywhereConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php
index b99516f7048..e496acfca40 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\SQLSrv\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php
index 13ce72a942f..4ffb451de3d 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\SQLSrv\SQLSrvConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php b/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php
index 90244cd2ac8..63cc84c41d3 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Driver\IBMDB2\DB2Statement;
diff --git a/tests/Doctrine/Tests/DBAL/DriverManagerTest.php b/tests/Doctrine/Tests/DBAL/DriverManagerTest.php
index c454bbea2e3..7dbb4f5bdd0 100644
--- a/tests/Doctrine/Tests/DBAL/DriverManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/DriverManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php b/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php
index 0f9be11edda..acfdd1ecab1 100644
--- a/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php
+++ b/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Events;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php b/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php
index 2ea510a0543..372016f486c 100644
--- a/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php
+++ b/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Events;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php b/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php
index f42458de74d..fbb8307b8ae 100644
--- a/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php
+++ b/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Events;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php b/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php
index 54cfea89596..b545fbefd4a 100644
--- a/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Exception;
 
 use Doctrine\DBAL\Exception\InvalidArgumentException;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php b/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php
index 69094c97838..62d73dd3e91 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Driver\OCI8\Driver as OCI8Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php
index ad86f9c87d1..4ac0bd1b455 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php b/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php
index df266d3fdc6..08325cfab72 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use DateTime;
@@ -904,8 +906,8 @@ public function testLocateExpression()
         $sql .= $platform->getLocateExpression("'foo'", 'test_string') . ' AS locate5, ';
         $sql .= $platform->getLocateExpression("'barfoobaz'", 'test_string') . ' AS locate6, ';
         $sql .= $platform->getLocateExpression("'bar'", 'test_string') . ' AS locate7, ';
-        $sql .= $platform->getLocateExpression('test_string', "'oo'", 2) . ' AS locate8, ';
-        $sql .= $platform->getLocateExpression('test_string', "'oo'", 3) . ' AS locate9 ';
+        $sql .= $platform->getLocateExpression('test_string', "'oo'", '2') . ' AS locate8, ';
+        $sql .= $platform->getLocateExpression('test_string', "'oo'", '3') . ' AS locate9 ';
         $sql .= 'FROM fetch_table';
 
         $row = $this->connection->fetchAssoc($sql);
@@ -995,8 +997,8 @@ public function testBitComparisonExpressionSupport()
         $sql[] = 'SELECT ';
         $sql[] = 'test_int, ';
         $sql[] = 'test_string, ';
-        $sql[] = $platform->getBitOrComparisonExpression('test_int', 2) . ' AS bit_or, ';
-        $sql[] = $platform->getBitAndComparisonExpression('test_int', 2) . ' AS bit_and ';
+        $sql[] = $platform->getBitOrComparisonExpression('test_int', '2') . ' AS bit_or, ';
+        $sql[] = $platform->getBitAndComparisonExpression('test_int', '2') . ' AS bit_and ';
         $sql[] = 'FROM fetch_table';
 
         $stmt = $this->connection->executeQuery(implode(PHP_EOL, $sql));
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php
index 2e145ca6c04..0770cf7f5ae 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php
index 144365e0d4d..3d7200bc14b 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\IBMDB2\DB2Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php
index d2ced1912c4..8856884f09d 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Mysqli\Driver;
@@ -61,7 +63,7 @@ private function getConnection(array $driverOptions)
             [
                 'host' => $GLOBALS['db_host'],
                 'dbname' => $GLOBALS['db_name'],
-                'port' => $GLOBALS['db_port'],
+                'port' => (int) $GLOBALS['db_port'],
             ],
             $GLOBALS['db_username'],
             $GLOBALS['db_password'],
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php
index a7b7338beed..ca0f5fd49c7 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Mysqli\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php
index b617b2bb0d3..4ccd7a589dd 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php
index 4e23a2a059a..f127473123f 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php
index fce2820bde8..ca7b62bfee4 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php
index e8ef3aa23c1..318f285a818 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver;
 
 use Doctrine\DBAL\Driver\PDOConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php
index 9fe297278f6..eb8453bb24a 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOMySql;
 
 use Doctrine\DBAL\Driver\PDOMySql\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php
index 3a5b44c22fa..640ad115e18 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOOracle;
 
 use Doctrine\DBAL\Driver\PDOOracle\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php
index 347982b24e5..bd3e09e56d0 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOPgSql;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php
index 7bfde54a6f3..995b62021cb 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver;
 
 use Doctrine\DBAL\DriverManager;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php
index 3df6d7a6540..882e42a938e 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOSqlite;
 
 use Doctrine\DBAL\Driver\PDOSqlite\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php
index 84d8bbfd822..005fed62056 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php
index e1df07bbac2..98f7503cb6d 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\SQLAnywhere\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php
index 4e42e863a46..d833a0fda1f 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php
index b67c8e571b4..dec46c48350 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\SQLAnywhere\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php
index 21413acec2f..efb440d197f 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\SQLSrv\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php
index 6f315716fa4..8124dd83d4d 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\SQLSrv\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php b/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php
index 841b4c599cb..e96ced74f9d 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Driver\ExceptionConverterDriver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php b/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php
index e172816f2af..a7c037bc951 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\Tests\DbalFunctionalTestCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php b/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php
index 99ca533e742..909f3d5d3fa 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Logging\SQLLogger;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php
index d927285e2a3..27a61ee101a 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Connections\MasterSlaveConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php b/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
index 88c28661634..cc3746fd69d 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php b/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php
index 4dec0809fb4..6a744161e44 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php
index 1ba37b61394..533a4f83038 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Driver\PDOConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php
index 5c1789e192d..b82cf0869c0 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Platform;
 
 use DateTimeImmutable;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php b/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php
index 64efb1aad6a..54fe2005bfb 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Platform;
 
 use Doctrine\DBAL\Schema\Comparator;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php b/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php
index 3a1ae7c8440..542aca07318 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Platform;
 
 use Doctrine\Tests\DbalFunctionalTestCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php b/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php
index 73308f8e7b3..e68e57fba1e 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\ColumnCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php b/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php
index 06f6c18bbe3..7ca4ee22814 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\Common\Cache\ArrayCache;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php
index 102fd1bb495..0ac6a58c478 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php
index 92e0f497a6d..6a6885880ae 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php
index 14e082c07dc..b5d9554d168 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php
index 597947d4575..bc15eff33e8 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -401,7 +403,7 @@ public function testJsonbColumn(string $type) : void
         $columns = $this->schemaManager->listTableColumns('test_jsonb');
 
         self::assertSame($type, $columns['foo']->getType()->getName());
-        self::assertTrue(true, $columns['foo']->getPlatformOption('jsonb'));
+        self::assertTrue($columns['foo']->getPlatformOption('jsonb'));
     }
 
     /**
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php
index 73eb07ea178..b70a3d6cce4 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema\Index;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php
index cb7f37f15d5..d2a3c03c7b2 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php
index 50fa10b4196..98995fa8ee3 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\Common\EventManager;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php
index a9f0ccdcfec..93fa85b78ed 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\DBALException;
@@ -97,7 +99,7 @@ public function testListForeignKeysFromExistingDatabase()
             new Schema\ForeignKeyConstraint(
                 ['log'],
                 'log',
-                [null],
+                [''],
                 'FK_3',
                 ['onUpdate' => 'SET NULL', 'onDelete' => 'NO ACTION', 'deferrable' => false, 'deferred' => false]
             ),
diff --git a/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php
index 23119f734f0..58bd96db631 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\DBALException;
@@ -358,7 +360,7 @@ public function testExecWithRedundantParameters() : void
 
         // we want to make sure the exception is thrown by the DBAL code, not by PHPUnit due to a PHP-level error,
         // but the wrapper connection wraps everything in a DBAL exception
-        $this->iniSet('error_reporting', 0);
+        $this->iniSet('error_reporting', '0');
 
         self::expectException(DBALException::class);
         $stmt->execute([null]);
diff --git a/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php b/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php
index a6721b88f8d..7897572e84c 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Id\TableGenerator;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php b/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php
index 8dae876dc0c..b18f282eb87 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php
index b18b6cbdaf5..217755f3a33 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php
index eeb9b7e24ed..460009eff3f 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php
index a9dbdb1e109..bc126f39286 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php
index 620b0a66249..001c8a3ad71 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Schema\Comparator;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php
index ab703e7dab1..820261e5742 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php
index 3e087b21b36..6e5e7601edb 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\Tests\DbalFunctionalTestCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php b/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php
index d5d917474ce..4b9670927ae 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php b/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php
index b253fea9e53..31d64b99044 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php b/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php
index b663f4959c7..a421398fe8d 100644
--- a/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php
+++ b/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Logging;
 
 use Doctrine\DBAL\Logging\DebugStack;
diff --git a/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php b/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php
index a0bf8936f50..8a731423079 100644
--- a/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php
+++ b/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Performance;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php
index d309a83c8d4..45b6dcf4c0b 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php
index 44acd8127cf..eb313fc500a 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\Common\EventManager;
@@ -273,7 +275,7 @@ public function testGeneratesForeignKeySqlOnlyWhenSupportingForeignKeys()
         }
     }
 
-    protected function getBitAndComparisonExpressionSql($value1, $value2)
+    protected function getBitAndComparisonExpressionSql(string $value1, string $value2)
     {
         return '(' . $value1 . ' & ' . $value2 . ')';
     }
@@ -283,11 +285,11 @@ protected function getBitAndComparisonExpressionSql($value1, $value2)
      */
     public function testGeneratesBitAndComparisonExpressionSql()
     {
-        $sql = $this->platform->getBitAndComparisonExpression(2, 4);
-        self::assertEquals($this->getBitAndComparisonExpressionSql(2, 4), $sql);
+        $sql = $this->platform->getBitAndComparisonExpression('2', '4');
+        self::assertEquals($this->getBitAndComparisonExpressionSql('2', '4'), $sql);
     }
 
-    protected function getBitOrComparisonExpressionSql($value1, $value2)
+    protected function getBitOrComparisonExpressionSql(string $value1, string $value2)
     {
         return '(' . $value1 . ' | ' . $value2 . ')';
     }
@@ -297,8 +299,8 @@ protected function getBitOrComparisonExpressionSql($value1, $value2)
      */
     public function testGeneratesBitOrComparisonExpressionSql()
     {
-        $sql = $this->platform->getBitOrComparisonExpression(2, 4);
-        self::assertEquals($this->getBitOrComparisonExpressionSql(2, 4), $sql);
+        $sql = $this->platform->getBitOrComparisonExpression('2', '4');
+        self::assertEquals($this->getBitOrComparisonExpressionSql('2', '4'), $sql);
     }
 
     public function getGenerateConstraintUniqueIndexSql()
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php
index 81d760e30b6..ed31a21fffc 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Column;
@@ -134,8 +136,8 @@ public function testGeneratesSqlSnippets()
         self::assertEquals('SIMILAR TO', $this->platform->getRegexpExpression(), 'Regular expression operator is not correct');
         self::assertEquals('"', $this->platform->getIdentifierQuoteCharacter(), 'Identifier quote character is not correct');
         self::assertEquals('column1 || column2 || column3', $this->platform->getConcatExpression('column1', 'column2', 'column3'), 'Concatenation expression is not correct');
-        self::assertEquals('SUBSTRING(column FROM 5)', $this->platform->getSubstringExpression('column', 5), 'Substring expression without length is not correct');
-        self::assertEquals('SUBSTRING(column FROM 1 FOR 5)', $this->platform->getSubstringExpression('column', 1, 5), 'Substring expression with length is not correct');
+        self::assertEquals('SUBSTRING(column FROM 5)', $this->platform->getSubstringExpression('column', '5'), 'Substring expression without length is not correct');
+        self::assertEquals('SUBSTRING(column FROM 1 FOR 5)', $this->platform->getSubstringExpression('column', '1', '5'), 'Substring expression with length is not correct');
     }
 
     public function testGeneratesTransactionCommands()
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php
index f06834913eb..214fc45e42e 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
index 14c668c0eab..2eae8df6489 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -290,7 +292,6 @@ public function testGeneratesDDLSnippets()
         self::assertEquals('DROP DATABASE foobar', $this->platform->getDropDatabaseSQL('foobar'));
         self::assertEquals('DECLARE GLOBAL TEMPORARY TABLE', $this->platform->getCreateTemporaryTableSnippetSQL());
         self::assertEquals('TRUNCATE foobar IMMEDIATE', $this->platform->getTruncateTableSQL('foobar'));
-        self::assertEquals('TRUNCATE foobar IMMEDIATE', $this->platform->getTruncateTableSQL('foobar'), true);
 
         $viewSql = 'SELECT * FROM footable';
         self::assertEquals('CREATE VIEW fooview AS ' . $viewSql, $this->platform->getCreateViewSQL('fooview', $viewSql));
@@ -313,28 +314,28 @@ public function testGeneratesSQLSnippets()
         self::assertEquals('CURRENT DATE', $this->platform->getCurrentDateSQL());
         self::assertEquals('CURRENT TIME', $this->platform->getCurrentTimeSQL());
         self::assertEquals('CURRENT TIMESTAMP', $this->platform->getCurrentTimestampSQL());
-        self::assertEquals("'1987/05/02' + 4 DAY", $this->platform->getDateAddDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("'1987/05/02' + 12 HOUR", $this->platform->getDateAddHourExpression("'1987/05/02'", 12));
-        self::assertEquals("'1987/05/02' + 2 MINUTE", $this->platform->getDateAddMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("'1987/05/02' + 102 MONTH", $this->platform->getDateAddMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("'1987/05/02' + (5 * 3) MONTH", $this->platform->getDateAddQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("'1987/05/02' + 1 SECOND", $this->platform->getDateAddSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("'1987/05/02' + (3 * 7) DAY", $this->platform->getDateAddWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("'1987/05/02' + 10 YEAR", $this->platform->getDateAddYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("'1987/05/02' + 4 DAY", $this->platform->getDateAddDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("'1987/05/02' + 12 HOUR", $this->platform->getDateAddHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("'1987/05/02' + 2 MINUTE", $this->platform->getDateAddMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("'1987/05/02' + 102 MONTH", $this->platform->getDateAddMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("'1987/05/02' + (5 * 3) MONTH", $this->platform->getDateAddQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("'1987/05/02' + 1 SECOND", $this->platform->getDateAddSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("'1987/05/02' + (3 * 7) DAY", $this->platform->getDateAddWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("'1987/05/02' + 10 YEAR", $this->platform->getDateAddYearsExpression("'1987/05/02'", '10'));
         self::assertEquals("DAYS('1987/05/02') - DAYS('1987/04/01')", $this->platform->getDateDiffExpression("'1987/05/02'", "'1987/04/01'"));
-        self::assertEquals("'1987/05/02' - 4 DAY", $this->platform->getDateSubDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("'1987/05/02' - 12 HOUR", $this->platform->getDateSubHourExpression("'1987/05/02'", 12));
-        self::assertEquals("'1987/05/02' - 2 MINUTE", $this->platform->getDateSubMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("'1987/05/02' - 102 MONTH", $this->platform->getDateSubMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("'1987/05/02' - (5 * 3) MONTH", $this->platform->getDateSubQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("'1987/05/02' - 1 SECOND", $this->platform->getDateSubSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("'1987/05/02' - (3 * 7) DAY", $this->platform->getDateSubWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("'1987/05/02' - 10 YEAR", $this->platform->getDateSubYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("'1987/05/02' - 4 DAY", $this->platform->getDateSubDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("'1987/05/02' - 12 HOUR", $this->platform->getDateSubHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("'1987/05/02' - 2 MINUTE", $this->platform->getDateSubMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("'1987/05/02' - 102 MONTH", $this->platform->getDateSubMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("'1987/05/02' - (5 * 3) MONTH", $this->platform->getDateSubQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("'1987/05/02' - 1 SECOND", $this->platform->getDateSubSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("'1987/05/02' - (3 * 7) DAY", $this->platform->getDateSubWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("'1987/05/02' - 10 YEAR", $this->platform->getDateSubYearsExpression("'1987/05/02'", '10'));
         self::assertEquals(' WITH RR USE AND KEEP UPDATE LOCKS', $this->platform->getForUpdateSQL());
         self::assertEquals('LOCATE(substring_column, string_column)', $this->platform->getLocateExpression('string_column', 'substring_column'));
-        self::assertEquals('LOCATE(substring_column, string_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', 1));
-        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', 5));
-        self::assertEquals('SUBSTR(column, 5, 2)', $this->platform->getSubstringExpression('column', 5, 2));
+        self::assertEquals('LOCATE(substring_column, string_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', '1'));
+        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', '5'));
+        self::assertEquals('SUBSTR(column, 5, 2)', $this->platform->getSubstringExpression('column', '5', '2'));
     }
 
     public function testModifiesLimitQuery()
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php
index 7171ad714d6..bfb9d893866 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\MariaDb1027Platform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php
index 52d7ca0708b..4cf615ac8c0 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\MySQL57Platform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php
index ec1f3181581..120d6764c1f 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php
index 79a84945399..a49ecaf71d8 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php
index 0bcf51e7435..f581dfb8ad6 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\PostgreSQL94Platform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php
index 9fdffcb951e..c4ca74f3535 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\PostgreSqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php b/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php
index b0c49ae6bb9..a809624ada1 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\Keywords\MySQLKeywords;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php
index 51989653425..e3833d0ccc7 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
@@ -306,7 +308,6 @@ public function testGeneratesDDLSnippets()
         self::assertEquals('STOP DATABASE "foobar" UNCONDITIONALLY', $this->platform->getStopDatabaseSQL('"foobar"'));
         self::assertEquals('STOP DATABASE "create" UNCONDITIONALLY', $this->platform->getStopDatabaseSQL('create'));
         self::assertEquals('TRUNCATE TABLE foobar', $this->platform->getTruncateTableSQL('foobar'));
-        self::assertEquals('TRUNCATE TABLE foobar', $this->platform->getTruncateTableSQL('foobar'), true);
 
         $viewSql = 'SELECT * FROM footable';
         self::assertEquals('CREATE VIEW fooview AS ' . $viewSql, $this->platform->getCreateViewSQL('fooview', $viewSql));
@@ -361,12 +362,12 @@ public function testGeneratesUniqueConstraintDeclarationSQL()
             'CONSTRAINT unique_constraint UNIQUE CLUSTERED (a, b)',
             $this->platform->getUniqueConstraintDeclarationSQL(
                 'unique_constraint',
-                new UniqueConstraint(null, ['a', 'b'], ['clustered'])
+                new UniqueConstraint('', ['a', 'b'], ['clustered'])
             )
         );
         self::assertEquals(
             'CONSTRAINT UNIQUE (a, b)',
-            $this->platform->getUniqueConstraintDeclarationSQL(null, new UniqueConstraint(null, ['a', 'b']))
+            $this->platform->getUniqueConstraintDeclarationSQL('', new UniqueConstraint('', ['a', 'b']))
         );
     }
 
@@ -615,31 +616,31 @@ public function testGeneratesSQLSnippets()
         self::assertEquals('CURRENT DATE', $this->platform->getCurrentDateSQL());
         self::assertEquals('CURRENT TIME', $this->platform->getCurrentTimeSQL());
         self::assertEquals('CURRENT TIMESTAMP', $this->platform->getCurrentTimestampSQL());
-        self::assertEquals("DATEADD(DAY, 4, '1987/05/02')", $this->platform->getDateAddDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("DATEADD(HOUR, 12, '1987/05/02')", $this->platform->getDateAddHourExpression("'1987/05/02'", 12));
-        self::assertEquals("DATEADD(MINUTE, 2, '1987/05/02')", $this->platform->getDateAddMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("DATEADD(MONTH, 102, '1987/05/02')", $this->platform->getDateAddMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("DATEADD(QUARTER, 5, '1987/05/02')", $this->platform->getDateAddQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("DATEADD(SECOND, 1, '1987/05/02')", $this->platform->getDateAddSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("DATEADD(WEEK, 3, '1987/05/02')", $this->platform->getDateAddWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("DATEADD(YEAR, 10, '1987/05/02')", $this->platform->getDateAddYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("DATEADD(DAY, 4, '1987/05/02')", $this->platform->getDateAddDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("DATEADD(HOUR, 12, '1987/05/02')", $this->platform->getDateAddHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("DATEADD(MINUTE, 2, '1987/05/02')", $this->platform->getDateAddMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("DATEADD(MONTH, 102, '1987/05/02')", $this->platform->getDateAddMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("DATEADD(QUARTER, 5, '1987/05/02')", $this->platform->getDateAddQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("DATEADD(SECOND, 1, '1987/05/02')", $this->platform->getDateAddSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("DATEADD(WEEK, 3, '1987/05/02')", $this->platform->getDateAddWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("DATEADD(YEAR, 10, '1987/05/02')", $this->platform->getDateAddYearsExpression("'1987/05/02'", '10'));
         self::assertEquals("DATEDIFF(day, '1987/04/01', '1987/05/02')", $this->platform->getDateDiffExpression("'1987/05/02'", "'1987/04/01'"));
-        self::assertEquals("DATEADD(DAY, -1 * 4, '1987/05/02')", $this->platform->getDateSubDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("DATEADD(HOUR, -1 * 12, '1987/05/02')", $this->platform->getDateSubHourExpression("'1987/05/02'", 12));
-        self::assertEquals("DATEADD(MINUTE, -1 * 2, '1987/05/02')", $this->platform->getDateSubMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("DATEADD(MONTH, -1 * 102, '1987/05/02')", $this->platform->getDateSubMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("DATEADD(QUARTER, -1 * 5, '1987/05/02')", $this->platform->getDateSubQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("DATEADD(SECOND, -1 * 1, '1987/05/02')", $this->platform->getDateSubSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("DATEADD(WEEK, -1 * 3, '1987/05/02')", $this->platform->getDateSubWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("DATEADD(YEAR, -1 * 10, '1987/05/02')", $this->platform->getDateSubYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("DATEADD(DAY, -1 * 4, '1987/05/02')", $this->platform->getDateSubDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("DATEADD(HOUR, -1 * 12, '1987/05/02')", $this->platform->getDateSubHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("DATEADD(MINUTE, -1 * 2, '1987/05/02')", $this->platform->getDateSubMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("DATEADD(MONTH, -1 * 102, '1987/05/02')", $this->platform->getDateSubMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("DATEADD(QUARTER, -1 * 5, '1987/05/02')", $this->platform->getDateSubQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("DATEADD(SECOND, -1 * 1, '1987/05/02')", $this->platform->getDateSubSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("DATEADD(WEEK, -1 * 3, '1987/05/02')", $this->platform->getDateSubWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("DATEADD(YEAR, -1 * 10, '1987/05/02')", $this->platform->getDateSubYearsExpression("'1987/05/02'", '10'));
         self::assertEquals('Y-m-d H:i:s.u', $this->platform->getDateTimeFormatString());
         self::assertEquals('H:i:s.u', $this->platform->getTimeFormatString());
         self::assertEquals('', $this->platform->getForUpdateSQL());
         self::assertEquals('LOCATE(string_column, substring_column)', $this->platform->getLocateExpression('string_column', 'substring_column'));
-        self::assertEquals('LOCATE(string_column, substring_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', 1));
+        self::assertEquals('LOCATE(string_column, substring_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', '1'));
         self::assertEquals("HASH(column, 'MD5')", $this->platform->getMd5Expression('column'));
-        self::assertEquals('SUBSTRING(column, 5)', $this->platform->getSubstringExpression('column', 5));
-        self::assertEquals('SUBSTRING(column, 5, 2)', $this->platform->getSubstringExpression('column', 5, 2));
+        self::assertEquals('SUBSTRING(column, 5)', $this->platform->getSubstringExpression('column', '5'));
+        self::assertEquals('SUBSTRING(column, 5, 2)', $this->platform->getSubstringExpression('column', '5', '2'));
         self::assertEquals('GLOBAL TEMPORARY', $this->platform->getTemporaryTableSQL());
         self::assertEquals(
             'LTRIM(column)',
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php
index 8aa6bc0cda3..ae993b67fd9 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\SQLAzurePlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php
index 91f8cfe2dc2..c57ad67fec4 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php
index f2f72719eff..17886c68e4c 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\LockMode;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php
index 79f07ef6d79..a17dd3e66a0 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
@@ -33,8 +35,8 @@ public function getGenerateTableWithMultiColumnUniqueIndexSql()
     public function testGeneratesSqlSnippets()
     {
         self::assertEquals('REGEXP', $this->platform->getRegexpExpression(), 'Regular expression operator is not correct');
-        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', 5), 'Substring expression without length is not correct');
-        self::assertEquals('SUBSTR(column, 0, 5)', $this->platform->getSubstringExpression('column', 0, 5), 'Substring expression with length is not correct');
+        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', '5'), 'Substring expression without length is not correct');
+        self::assertEquals('SUBSTR(column, 0, 5)', $this->platform->getSubstringExpression('column', '0', '5'), 'Substring expression with length is not correct');
     }
 
     public function testGeneratesTransactionCommands()
@@ -766,7 +768,7 @@ public function testQuotesTableNameInListTableForeignKeysSQL()
 
     public function testDateAddStaticNumberOfDays()
     {
-        self::assertSame("DATETIME(rentalBeginsOn,'+' || 12 || ' DAY')", $this->platform->getDateAddDaysExpression('rentalBeginsOn', 12));
+        self::assertSame("DATETIME(rentalBeginsOn,'+' || 12 || ' DAY')", $this->platform->getDateAddDaysExpression('rentalBeginsOn', '12'));
     }
 
     public function testDateAddNumberOfDaysFromColumn()
diff --git a/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php b/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php
index 622e030c245..2477efcd4d3 100644
--- a/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Portability;
 
 use Doctrine\DBAL\Driver\Statement as DriverStatement;
diff --git a/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php b/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php
index 512dfb08224..2b8c8b75a80 100644
--- a/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Query\Expression;
 
 use Doctrine\DBAL\Query\Expression\CompositeExpression;
diff --git a/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php b/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php
index d419f8d5fd4..73b8683da3e 100644
--- a/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php
+++ b/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Query\Expression;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php b/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php
index 4394ef38286..11b46008cea 100644
--- a/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php
+++ b/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Query;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php b/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php
index 414f909f870..29e67935df5 100644
--- a/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php
+++ b/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php b/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php
index 046118f91fa..ed43f70a391 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php b/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php
index caf93439244..b881b4acffb 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php b/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php
index 6395479b2ed..d072d60330a 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php
index 7d11c926750..a653430697e 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\Common\EventManager;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php b/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php
index 2c317fc5dea..07997351747 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php b/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php
index ad9e2bbbdb7..c5cebd2dfd6 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Index;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php
index 4646700e0e7..2b400afe78e 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\Common\EventManager;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php b/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php
index 568a4bfa79a..4fbdfcf755e 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php b/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php
index 8400e952ef6..d56cf849568 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php b/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php
index 5618feeefdb..19d991e7e9d 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Schema;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php b/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php
index b3a72017c16..f91eed899be 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Sequence;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php
index 7b3031624af..4262fb24544 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php b/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php
index 80d43e0e1b4..b40494f702c 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php b/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php
index ae1682739c6..2c862fa4d05 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/TableTest.php b/tests/Doctrine/Tests/DBAL/Schema/TableTest.php
index 4dc01fff7f4..1f7bdf04856 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/TableTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/TableTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php
index e35583182a1..a6ef5597214 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php
index b2aff283871..5b59e8d1552 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php
index c3e52b0ffaf..f08f921cfee 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php
index 4ebfd1cac54..dd8e68e3bd4 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php
index 4985605c60d..d1dcf3938b2 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding;
 
 use Doctrine\DBAL\DriverManager;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php
index f1f6cc0e2e7..91e92daefd6 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php
index 5424c7bb676..694315d171c 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php
index 8a99ea70879..fc35b098ad0 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Sharding\SQLAzure\SQLAzureFederationsSynchronizer;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php
index 94634dadb69..aa6f41af4a4 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Platforms\SQLAzurePlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php
index 20e479a3e00..8a115fab864 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Sharding\SQLAzure\SQLAzureFederationsSynchronizer;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php
index 3a0d37ab4ce..441a42e6fc8 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php b/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php
index 0c78b5c1771..e1befbf921a 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\ShardChoser;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/tests/Doctrine/Tests/DBAL/StatementTest.php b/tests/Doctrine/Tests/DBAL/StatementTest.php
index 81e6314eae5..d5c3b635dd6 100644
--- a/tests/Doctrine/Tests/DBAL/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Configuration;
diff --git a/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php b/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php
index eb06ddc350b..076ebd9084c 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\Console;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php b/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php
index 2aae261561f..f82d466a097 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools;
 
 use ArrayIterator;
diff --git a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php
index 19e7020c340..106f265680e 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\TestAsset;
 
 final class ChildClass extends ParentClass
diff --git a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php
index 623a6c02690..3964a48e7d0 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\TestAsset;
 
 final class ChildWithSameAttributesClass extends ParentClass
diff --git a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php
index 62831aef198..cf4f2c099c1 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\TestAsset;
 
 abstract class ParentClass
diff --git a/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php b/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php
index 6f09cbf2bc0..3e5e0ec6bb6 100644
--- a/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php b/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php
index 3e73c96e7c9..eb5056f682c 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php b/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php
index d5a95e30c3d..f0639c7c679 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BlobTest.php b/tests/Doctrine/Tests/DBAL/Types/BlobTest.php
index 69a29c6b1db..b2cac3b7d18 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BlobTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BlobTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php b/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php
index af84fbf00d2..594283d0072 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php b/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php
index 3030899cd51..6c6dd71e727 100644
--- a/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Types\ConversionException;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php
index 38cf0a98a33..6e8adc83884 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php b/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php
index 710474257af..7a32b7fb24b 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateInterval;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTest.php
index e7c76ba77ff..4a0182cbca5 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php
index 4c2ed8e104e..516317cee54 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
@@ -103,6 +105,8 @@ public function testConvertsDateTimeStringWithMicrosecondsToPHPValue()
 
     public function testThrowsExceptionDuringConversionToPHPValueWithInvalidDateTimeString()
     {
+        $this->platform->getDateTimeFormatString()->willReturn('Y-m-d H:i:s')->shouldBeCalled();
+
         $this->expectException(ConversionException::class);
 
         $this->type->convertToPHPValue('invalid datetime string', $this->platform->reveal());
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php
index 615c14d584d..923f22151b4 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php
index aa602b629c2..359d5b1b28c 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
@@ -91,6 +93,8 @@ public function testConvertsDateTimeWithTimezoneStringToPHPValue()
 
     public function testThrowsExceptionDuringConversionToPHPValueWithInvalidDateTimeWithTimezoneString()
     {
+        $this->platform->getDateTimeTzFormatString()->willReturn('Y-m-d H:i:s T')->shouldBeCalled();
+
         $this->expectException(ConversionException::class);
 
         $this->type->convertToPHPValue('invalid datetime with timezone string', $this->platform->reveal());
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php
index 419974c6b09..7407c70beb3 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php b/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php
index 7087d2a6a49..f071ebe4a0a 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/FloatTest.php b/tests/Doctrine/Tests/DBAL/Types/FloatTest.php
index 6daffd7d29b..37452c296cf 100644
--- a/tests/Doctrine/Tests/DBAL/Types/FloatTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/FloatTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php
index bbd309bea6d..7fc1900e344 100644
--- a/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php b/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php
index 789de21e208..3644f26aee3 100644
--- a/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php b/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php
index 730234dc85f..d61bc27b654 100644
--- a/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/tests/Doctrine/Tests/DBAL/Types/JsonTest.php b/tests/Doctrine/Tests/DBAL/Types/JsonTest.php
index 123291f53b6..94a21e07987 100644
--- a/tests/Doctrine/Tests/DBAL/Types/JsonTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/JsonTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php b/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php
index f8852ff1640..49d30757c5d 100644
--- a/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php b/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php
index 8aecc6649fa..7cb6c65e941 100644
--- a/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/StringTest.php b/tests/Doctrine/Tests/DBAL/Types/StringTest.php
index 2c725686d1c..88dc72cb6bc 100644
--- a/tests/Doctrine/Tests/DBAL/Types/StringTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/StringTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php
index a374cf1015f..3e93f3a921b 100644
--- a/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/TimeTest.php b/tests/Doctrine/Tests/DBAL/Types/TimeTest.php
index 1b254730092..9c677487296 100644
--- a/tests/Doctrine/Tests/DBAL/Types/TimeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/TimeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Types\ConversionException;
diff --git a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php
index b948f22af77..f38fcef6e5f 100644
--- a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php
index 0807b25f022..311eb4db9bb 100644
--- a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
@@ -21,6 +23,10 @@ class VarDateTimeTest extends DbalTestCase
     protected function setUp() : void
     {
         $this->platform = $this->createMock(AbstractPlatform::class);
+        $this->platform->expects($this->any())
+            ->method('getDateTimeFormatString')
+            ->will($this->returnValue('U'));
+
         if (! Type::hasType('vardatetime')) {
             Type::addType('vardatetime', VarDateTimeType::class);
         }
@@ -31,7 +37,7 @@ public function testDateTimeConvertsToDatabaseValue()
     {
         $date = new DateTime('1985-09-01 10:10:10');
 
-        $expected = $date->format($this->platform->getDateTimeTzFormatString());
+        $expected = $date->format($this->platform->getDateTimeFormatString());
         $actual   = $this->type->convertToDatabaseValue($date, $this->platform);
 
         self::assertEquals($expected, $actual);
diff --git a/tests/Doctrine/Tests/DBAL/UtilTest.php b/tests/Doctrine/Tests/DBAL/UtilTest.php
index e7800fceba3..6bec241c483 100644
--- a/tests/Doctrine/Tests/DBAL/UtilTest.php
+++ b/tests/Doctrine/Tests/DBAL/UtilTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Driver\OCI8\OCI8Statement;
diff --git a/tests/Doctrine/Tests/DbalFunctionalTestCase.php b/tests/Doctrine/Tests/DbalFunctionalTestCase.php
index 2ae17cf9165..f34a5fd0d0e 100644
--- a/tests/Doctrine/Tests/DbalFunctionalTestCase.php
+++ b/tests/Doctrine/Tests/DbalFunctionalTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DbalPerformanceTestCase.php b/tests/Doctrine/Tests/DbalPerformanceTestCase.php
index f9bb40df38c..3c8a7b32b22 100644
--- a/tests/Doctrine/Tests/DbalPerformanceTestCase.php
+++ b/tests/Doctrine/Tests/DbalPerformanceTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use function microtime;
diff --git a/tests/Doctrine/Tests/DbalPerformanceTestListener.php b/tests/Doctrine/Tests/DbalPerformanceTestListener.php
index e9265c0f35f..6e4206289ad 100644
--- a/tests/Doctrine/Tests/DbalPerformanceTestListener.php
+++ b/tests/Doctrine/Tests/DbalPerformanceTestListener.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use PHPUnit\Framework\Test;
diff --git a/tests/Doctrine/Tests/DbalTestCase.php b/tests/Doctrine/Tests/DbalTestCase.php
index 8664141c03e..a059eae7745 100644
--- a/tests/Doctrine/Tests/DbalTestCase.php
+++ b/tests/Doctrine/Tests/DbalTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Doctrine/Tests/Mocks/DriverResultStatementMock.php b/tests/Doctrine/Tests/Mocks/DriverResultStatementMock.php
index 46573c39494..c48d70c2427 100644
--- a/tests/Doctrine/Tests/Mocks/DriverResultStatementMock.php
+++ b/tests/Doctrine/Tests/Mocks/DriverResultStatementMock.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Mocks;
 
 use Doctrine\DBAL\Driver\ResultStatement;
diff --git a/tests/Doctrine/Tests/Mocks/DriverStatementMock.php b/tests/Doctrine/Tests/Mocks/DriverStatementMock.php
index 5c14d6962e2..e4258038197 100644
--- a/tests/Doctrine/Tests/Mocks/DriverStatementMock.php
+++ b/tests/Doctrine/Tests/Mocks/DriverStatementMock.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Mocks;
 
 use Doctrine\DBAL\Driver\Statement;
diff --git a/tests/Doctrine/Tests/Mocks/ServerInfoAwareConnectionMock.php b/tests/Doctrine/Tests/Mocks/ServerInfoAwareConnectionMock.php
index 75c3761e11c..e7a136a09df 100644
--- a/tests/Doctrine/Tests/Mocks/ServerInfoAwareConnectionMock.php
+++ b/tests/Doctrine/Tests/Mocks/ServerInfoAwareConnectionMock.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Mocks;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/tests/Doctrine/Tests/Mocks/VersionAwarePlatformDriverMock.php b/tests/Doctrine/Tests/Mocks/VersionAwarePlatformDriverMock.php
index 7e2ca9c37aa..986a2d1ac44 100644
--- a/tests/Doctrine/Tests/Mocks/VersionAwarePlatformDriverMock.php
+++ b/tests/Doctrine/Tests/Mocks/VersionAwarePlatformDriverMock.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Mocks;
 
 use Doctrine\DBAL\Driver;
diff --git a/tests/Doctrine/Tests/TestUtil.php b/tests/Doctrine/Tests/TestUtil.php
index 0ff5a42ce8c..ef2f11322af 100644
--- a/tests/Doctrine/Tests/TestUtil.php
+++ b/tests/Doctrine/Tests/TestUtil.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use Doctrine\DBAL\Connection;
@@ -151,7 +153,7 @@ private static function getParamsForTemporaryConnection()
             'password' => $GLOBALS['tmpdb_password'],
             'host' => $GLOBALS['tmpdb_host'],
             'dbname' => null,
-            'port' => $GLOBALS['tmpdb_port'],
+            'port' => (int) $GLOBALS['tmpdb_port'],
         ];
 
         if (isset($GLOBALS['tmpdb_name'])) {
@@ -177,7 +179,7 @@ private static function getParamsForMainConnection()
             'password' => $GLOBALS['db_password'],
             'host' => $GLOBALS['db_host'],
             'dbname' => $GLOBALS['db_name'],
-            'port' => $GLOBALS['db_port'],
+            'port' => (int) $GLOBALS['db_port'],
         ];
 
         if (isset($GLOBALS['db_server'])) {
diff --git a/tests/Doctrine/Tests/Types/CommentedType.php b/tests/Doctrine/Tests/Types/CommentedType.php
index cbe98b2324b..0b02bcef995 100644
--- a/tests/Doctrine/Tests/Types/CommentedType.php
+++ b/tests/Doctrine/Tests/Types/CommentedType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/Types/MySqlPointType.php b/tests/Doctrine/Tests/Types/MySqlPointType.php
index f4740769b8b..46b9121c628 100644
--- a/tests/Doctrine/Tests/Types/MySqlPointType.php
+++ b/tests/Doctrine/Tests/Types/MySqlPointType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;