Allow to specify arbitrary SQL expression in AbstractPlatform::getDummySelectSQL()

For testing purposes and not only, it may be needed to evaluate an arbitrary SQL expression (see doctrine#3013, doctrine#3108). Instead of doing `str_replace()` on an expected string, one could specify the expression explicitly.

Author: morozov

lib/Doctrine/DBAL/Platforms/AbstractPlatform.php

@@ -3497,9 +3497,9 @@ public function getTruncateTableSQL($tableName, $cascade = false)
      *
      * @return string
      */
-    public function getDummySelectSQL()
+    public function getDummySelectSQL(string $expression = '1')
     {
-        return 'SELECT 1';
+        return sprintf('SELECT %s', $expression);
     }
 
     /**

lib/Doctrine/DBAL/Platforms/DB2Platform.php

@@ -861,9 +861,9 @@ public function getForUpdateSQL()
     /**
      * {@inheritDoc}
      */
-    public function getDummySelectSQL()
+    public function getDummySelectSQL(string $expression = '1')
     {
-        return 'SELECT 1 FROM sysibm.sysdummy1';
+        return sprintf('SELECT %s FROM sysibm.sysdummy1', $expression);
     }
 
     /**

lib/Doctrine/DBAL/Platforms/OraclePlatform.php

@@ -1118,9 +1118,9 @@ public function getTruncateTableSQL($tableName, $cascade = false)
     /**
      * {@inheritDoc}
      */
-    public function getDummySelectSQL()
+    public function getDummySelectSQL(string $expression = '1')
     {
-        return 'SELECT 1 FROM DUAL';
+        return sprintf('SELECT %s FROM DUAL', $expression);
     }
 
     /**

tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php

@@ -13,16 +13,16 @@ public function testFetchLikeExpressionResult() : void
         $string           = '_25% off_ your next purchase \o/ [$̲̅(̲̅5̲̅)̲̅$̲̅] (^̮^)';
         $escapeChar       = '!';
         $databasePlatform = $this->_conn->getDatabasePlatform();
-        $stmt             = $this->_conn->prepare(str_replace(
-            '1',
-            sprintf(
-                "(CASE WHEN '%s' LIKE '%s' ESCAPE '%s' THEN 1 ELSE 0 END)",
-                $string,
-                $databasePlatform->escapeStringForLike($string, $escapeChar),
-                $escapeChar
-            ),
-            $databasePlatform->getDummySelectSQL()
-        ));
+        $stmt             = $this->_conn->prepare(
+            $databasePlatform->getDummySelectSQL(
+                sprintf(
+                    "(CASE WHEN '%s' LIKE '%s' ESCAPE '%s' THEN 1 ELSE 0 END)",
+                    $string,
+                    $databasePlatform->escapeStringForLike($string, $escapeChar),
+                    $escapeChar
+                )
+            )
+        );
         $stmt->execute();
         $this->assertTrue((bool) $stmt->fetchColumn());
     }