Merge pull request #2315 from ClickHouse/tweak-databasemetadata

Adjust getIndexInfo to return an empty ResultSet instead of a null value

Author: Paultagoras

jdbc-v2/src/main/java/com/clickhouse/jdbc/ConnectionImpl.java

@@ -10,6 +10,7 @@
 import com.clickhouse.jdbc.internal.JdbcConfiguration;
 import com.clickhouse.jdbc.internal.ExceptionUtils;
 import com.clickhouse.jdbc.internal.JdbcUtils;
+import com.clickhouse.jdbc.metadata.DatabaseMetaDataImpl;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -54,7 +55,7 @@ public class ConnectionImpl implements Connection, JdbcV2Wrapper {
     private String appName;
     private QuerySettings defaultQuerySettings;
 
-    private final com.clickhouse.jdbc.metadata.DatabaseMetaData metadata;
+    private final DatabaseMetaDataImpl metadata;
     protected final Calendar defaultCalendar;
 
     public ConnectionImpl(String url, Properties info) throws SQLException {
@@ -96,7 +97,7 @@ public ConnectionImpl(String url, Properties info) throws SQLException {
                     .serverSetting(ServerSettings.ASYNC_INSERT, "0")
                     .serverSetting(ServerSettings.WAIT_END_OF_QUERY, "0");
 
-            this.metadata = new com.clickhouse.jdbc.metadata.DatabaseMetaData(this, false, url);
+            this.metadata = new DatabaseMetaDataImpl(this, false, url);
             this.defaultCalendar = Calendar.getInstance();
         } catch (SQLException e) {
             throw e;

jdbc-v2/src/main/java/com/clickhouse/jdbc/metadata/DatabaseMetaData.java renamed to jdbc-v2/src/main/java/com/clickhouse/jdbc/metadata/DatabaseMetaDataImpl.java

@@ -23,8 +23,8 @@
 import java.sql.SQLType;
 import java.util.Arrays;
 
-public class DatabaseMetaData implements java.sql.DatabaseMetaData, JdbcV2Wrapper {
-    private static final Logger log = LoggerFactory.getLogger(DatabaseMetaData.class);
+public class DatabaseMetaDataImpl implements java.sql.DatabaseMetaData, JdbcV2Wrapper {
+    private static final Logger log = LoggerFactory.getLogger(DatabaseMetaDataImpl.class);
     public static final String[] TABLE_TYPES = new String[] { "DICTIONARY", "LOG TABLE", "MEMORY TABLE",
             "REMOTE TABLE", "TABLE", "VIEW", "SYSTEM TABLE", "TEMPORARY TABLE" };
 
@@ -42,7 +42,7 @@ public class DatabaseMetaData implements java.sql.DatabaseMetaData, JdbcV2Wrappe
      * @param connection - connection for which metadata is created
      * @param useCatalogs - if true then getCatalogs() will return non-empty list (not implemented yet)
      */
-    public DatabaseMetaData(ConnectionImpl connection, boolean useCatalogs, String url) throws SQLFeatureNotSupportedException {
+    public DatabaseMetaDataImpl(ConnectionImpl connection, boolean useCatalogs, String url) throws SQLFeatureNotSupportedException {
         if (useCatalogs) {
             throw new SQLFeatureNotSupportedException("Catalogs are not supported yet", ExceptionUtils.SQL_STATE_FEATURE_NOT_SUPPORTED);
         }
@@ -864,7 +864,7 @@ public ResultSet getColumns(String catalog, String schemaPattern, String tableNa
                 " ORDER BY TABLE_SCHEM, TABLE_NAME, ORDINAL_POSITION";
         try {
             return new MetadataResultSet((ResultSetImpl) connection.createStatement().executeQuery(sql))
-                    .transform(DATA_TYPE_COL.getColumnName(), DATA_TYPE_COL, DatabaseMetaData::columnDataTypeToSqlType);
+                    .transform(DATA_TYPE_COL.getColumnName(), DATA_TYPE_COL, DatabaseMetaDataImpl::columnDataTypeToSqlType);
         } catch (Exception e) {
             throw ExceptionUtils.toSqlState(e);
         }
@@ -1002,8 +1002,8 @@ public ResultSet getCrossReference(String parentCatalog, String parentSchema, St
     public ResultSet getTypeInfo() throws SQLException {
         try {
             return new MetadataResultSet((ResultSetImpl) connection.createStatement().executeQuery(DATA_TYPE_INFO_SQL))
-                    .transform(DATA_TYPE_COL.getColumnName(), DATA_TYPE_COL, DatabaseMetaData::dataTypeToSqlTypeInt)
-                    .transform(NULLABLE_COL.getColumnName(), NULLABLE_COL, DatabaseMetaData::dataTypeNullability);
+                    .transform(DATA_TYPE_COL.getColumnName(), DATA_TYPE_COL, DatabaseMetaDataImpl::dataTypeToSqlTypeInt)
+                    .transform(NULLABLE_COL.getColumnName(), NULLABLE_COL, DatabaseMetaDataImpl::dataTypeNullability);
         } catch (Exception e) {
             throw ExceptionUtils.toSqlState(e);
         }
@@ -1065,7 +1065,14 @@ private static String getDataTypeInfoSql() {
 
     @Override
     public ResultSet getIndexInfo(String catalog, String schema, String table, boolean unique, boolean approximate) throws SQLException {
-        return null;
+        try {
+            String sql = "SELECT null AS TABLE_CAT, null AS TABLE_SCHEM, null AS TABLE_NAME, null AS NON_UNIQUE," +
+                    " null AS INDEX_QUALIFIER, null AS INDEX_NAME, null AS TYPE, null AS ORDINAL_POSITION, null AS COLUMN_NAME, null AS ASC_OR_DESC," +
+                    " null AS CARDINALITY, null AS PAGES, null AS FILTER_CONDITION LIMIT 0";
+            return connection.createStatement().executeQuery(sql);
+        } catch (Exception e) {
+            throw ExceptionUtils.toSqlState(e);
+        }
     }
 
     @Override

jdbc-v2/src/test/java/com/clickhouse/jdbc/metadata/DatabaseMetaDataTest.java

@@ -178,7 +178,7 @@ public void testGetTableTypes() throws Exception {
         try (Connection conn = getJdbcConnection()) {
             DatabaseMetaData dbmd = conn.getMetaData();
             ResultSet rs = dbmd.getTableTypes();
-            List<String> sortedTypes = Arrays.asList(com.clickhouse.jdbc.metadata.DatabaseMetaData.TABLE_TYPES);
+            List<String> sortedTypes = Arrays.asList(DatabaseMetaDataImpl.TABLE_TYPES);
             Collections.sort(sortedTypes);
             for (String type: sortedTypes) {
                 assertTrue(rs.next());
@@ -316,4 +316,14 @@ public void testGetDriverVersion() throws Exception {
             assertNotEquals(version, "unknown");
         }
     }
+
+
+    @Test(groups = { "integration" })
+    public void testGetIndexInfo() throws Exception {
+        try (Connection conn = getJdbcConnection()) {
+            DatabaseMetaData dbmd = conn.getMetaData();
+            ResultSet rs = dbmd.getIndexInfo(null, null, "numbers", false, false);
+            assertFalse(rs.next());
+        }
+    }
 }