HHH-20050:- Create Spanner PostgreSQL dialect (Basic version)

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SpannerPostgreSQLDialect.java

@@ -0,0 +1,226 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.community.dialect;
+
+import org.hibernate.community.dialect.sequence.SpannerPostgreSQLSequenceSupport;
+import org.hibernate.dialect.DatabaseVersion;
+import org.hibernate.dialect.PostgreSQLDialect;
+import org.hibernate.dialect.SimpleDatabaseVersion;
+import org.hibernate.dialect.sequence.SequenceSupport;
+import org.hibernate.dialect.unique.AlterTableUniqueIndexDelegate;
+import org.hibernate.dialect.unique.UniqueDelegate;
+import org.hibernate.engine.jdbc.dialect.spi.DialectResolutionInfo;
+import org.hibernate.procedure.internal.StandardCallableStatementSupport;
+import org.hibernate.procedure.spi.CallableStatementSupport;
+import org.hibernate.tool.schema.internal.StandardTableExporter;
+
+public class SpannerPostgreSQLDialect extends PostgreSQLDialect {
+
+	private final UniqueDelegate SPANNER_UNIQUE_DELEGATE = new AlterTableUniqueIndexDelegate( this );
+	private final StandardTableExporter SPANNER_TABLE_EXPORTER = new SpannerPostgreSQLTableExporter( this );
+
+	public SpannerPostgreSQLDialect() {
+		super();
+	}
+
+	public SpannerPostgreSQLDialect(DialectResolutionInfo info) {
+		super( info );
+	}
+
+	public SpannerPostgreSQLDialect(DatabaseVersion version) {
+		super( version );
+	}
+
+	@Override
+	protected DatabaseVersion getMinimumSupportedVersion() {
+		return SimpleDatabaseVersion.ZERO_VERSION;
+	}
+
+	@Override
+	public StandardTableExporter getTableExporter() {
+		return SPANNER_TABLE_EXPORTER;
+	}
+
+	@Override
+	public UniqueDelegate getUniqueDelegate() {
+		return SPANNER_UNIQUE_DELEGATE;
+	}
+
+	@Override
+	public SequenceSupport getSequenceSupport() {
+		return SpannerPostgreSQLSequenceSupport.INSTANCE;
+	}
+
+	@Override
+	public boolean supportsUserDefinedTypes() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsFilterClause() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsRecursiveCycleUsingClause() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsRecursiveSearchClause() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsUniqueConstraints() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsRowValueConstructorGtLtSyntax() {
+		return false;
+	}
+
+	// ALL subqueries with operators other than <>/!= are not supported
+	@Override
+	public boolean supportsRowValueConstructorSyntaxInQuantifiedPredicates() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsRowValueConstructorSyntaxInInSubQuery() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsCaseInsensitiveLike() {
+		return false;
+	}
+
+	@Override
+	public String currentTimestamp() {
+		return currentTimestampWithTimeZone();
+	}
+
+	@Override
+	public String currentTime() {
+		return currentTimestampWithTimeZone();
+	}
+
+	@Override
+	public boolean supportsLateral() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsFromClauseInUpdate() {
+		return false;
+	}
+
+	@Override
+	public int getMaxVarcharLength() {
+		return 2_621_440;
+	}
+
+	@Override
+	public int getMaxVarbinaryLength() {
+		//max is equivalent 10 MiB
+		return 10_485_760;
+	}
+
+	@Override
+	public String getCurrentSchemaCommand() {
+		return "";
+	}
+
+	@Override
+	public boolean supportsCommentOn() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsWindowFunctions() {
+		return false;
+	}
+
+	@Override
+	public String getAddForeignKeyConstraintString(
+			String constraintName,
+			String[] foreignKey,
+			String referencedTable,
+			String[] primaryKey,
+			boolean referencesPrimaryKey) {
+		if ( !referencesPrimaryKey ) {
+			throw new UnsupportedOperationException(
+					"Cannot add foreign keys without reference table's primary key" );
+		}
+		return super.getAddForeignKeyConstraintString( constraintName, foreignKey, referencedTable, primaryKey, referencesPrimaryKey );
+	}
+
+	@Override
+	public boolean canBatchTruncate() {
+		return false;
+	}
+
+	@Override
+	public String rowId(String rowId) {
+		return null;
+	}
+
+	@Override
+	public boolean supportsRowConstructor() {
+		return false;
+	}
+
+	@Override
+	public String getTruncateTableStatement(String tableName) {
+		return "delete from " + tableName;
+	}
+
+	@Override
+	public String getBeforeDropStatement() {
+		return null;
+	}
+
+	@Override
+	public String getCascadeConstraintsString() {
+		return "";
+	}
+
+	@Override
+	public boolean supportsIfExistsBeforeConstraintName() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsIfExistsAfterAlterTable() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsDistinctFromPredicate() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsPartitionBy() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsNonQueryWithCTE() {
+		return false;
+	}
+
+	@Override
+	public boolean supportsRecursiveCTE() {
+		return false;
+	}
+
+	@Override
+	public CallableStatementSupport getCallableStatementSupport() {
+		return StandardCallableStatementSupport.NO_REF_CURSOR_INSTANCE;
+	}
+}

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SpannerPostgreSQLTableExporter.java

@@ -0,0 +1,82 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.community.dialect;
+
+import org.hibernate.boot.Metadata;
+import org.hibernate.boot.model.relational.SqlStringGenerationContext;
+import org.hibernate.dialect.Dialect;
+import org.hibernate.mapping.Column;
+import org.hibernate.tool.schema.internal.ColumnValue;
+import org.hibernate.mapping.Index;
+import org.hibernate.mapping.PrimaryKey;
+import org.hibernate.mapping.Table;
+import org.hibernate.mapping.UniqueKey;
+import org.hibernate.tool.schema.internal.StandardTableExporter;
+
+import java.sql.Types;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Stream;
+
+public class SpannerPostgreSQLTableExporter extends StandardTableExporter {
+
+	public SpannerPostgreSQLTableExporter(Dialect dialect) {
+		super( dialect );
+	}
+
+	@Override
+	public String[] getSqlCreateStrings(Table table, Metadata metadata, SqlStringGenerationContext context) {
+		// Spanner mandates that primary key should be present in all the tables. For element collection tables,
+		// there will be no primary key. In order to fix the problem, we randomly generate the ID column
+		// with BIT_REVERSED_POSITIVE sequence
+		if ( !table.hasPrimaryKey() && !table.getForeignKeyCollection().isEmpty() ) {
+			Column column = getAutoGeneratedPrimaryKeyColumn( table, metadata );
+			table.addColumn( column );
+
+			PrimaryKey primaryKey = new PrimaryKey( table );
+			primaryKey.addColumn( column );
+
+			table.setPrimaryKey( primaryKey );
+		}
+
+		return super.getSqlCreateStrings( table, metadata, context );
+	}
+
+	@Override
+	public String[] getSqlDropStrings(Table table, Metadata metadata, SqlStringGenerationContext context) {
+		// Spanner requires the indexes to be dropped before dropping the table
+		List<String> sqlDropIndexStrings = new ArrayList<>();
+		for ( Index index : table.getIndexes().values() ) {
+			sqlDropIndexStrings.add( sqlDropIndexString(index.getName()) );
+		}
+		// Spanner requires all the unique indexes to be dropped before dropping the tables
+		for ( UniqueKey uniqueKey : table.getUniqueKeys().values() ) {
+			sqlDropIndexStrings.add( sqlDropIndexString(uniqueKey.getName()) );
+		}
+		for ( Column column : table.getColumns() ) {
+			if ( column.isUnique() ) {
+				sqlDropIndexStrings.add( sqlDropIndexString(column.getUniqueKeyName()) );
+			}
+		}
+		String[] sqlDropStrings = super.getSqlDropStrings( table, metadata, context );
+		return Stream.concat( sqlDropIndexStrings.stream(), Stream.of( sqlDropStrings ) )
+				.toArray( String[]::new );
+	}
+
+	private String sqlDropIndexString(String indexName) {
+		return "drop index if exists " + indexName;
+	}
+
+	private Column getAutoGeneratedPrimaryKeyColumn(Table table, Metadata metadata) {
+		Column column = new Column( "rowid" );
+		column.setSqlTypeCode( Types.BIGINT );
+		column.setNullable( false );
+		column.setSqlType( "bigint" );
+		column.setOptions( "hidden" );
+		column.setIdentity( true );
+		column.setValue( new ColumnValue( metadata.getDatabase(), table, column, metadata.getDatabase().getTypeConfiguration().getBasicTypeForJavaType( Long.class ) ) );
+		return column;
+	}
+}

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/sequence/SpannerPostgreSQLSequenceSupport.java

@@ -0,0 +1,29 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.community.dialect.sequence;
+
+import org.hibernate.MappingException;
+import org.hibernate.dialect.sequence.PostgreSQLSequenceSupport;
+import org.hibernate.dialect.sequence.SequenceSupport;
+
+public class SpannerPostgreSQLSequenceSupport extends PostgreSQLSequenceSupport {
+
+	public static final SequenceSupport INSTANCE = new SpannerPostgreSQLSequenceSupport();
+
+	@Override
+	public String getCreateSequenceString(String sequenceName, int initialValue, int incrementSize) throws MappingException {
+		if ( incrementSize == 0 ) {
+			throw new MappingException( "Unable to create the sequence [" + sequenceName + "]: the increment size must not be 0" );
+		}
+		return getCreateSequenceString( sequenceName )
+			+ startingValue( initialValue, incrementSize )
+			+ " start counter with " + initialValue;
+	}
+
+	@Override
+	public String getRestartSequenceString(String sequenceName, long startWith) {
+		return "alter sequence " + sequenceName + " restart counter with " + startWith;
+	}
+}

hibernate-core/src/main/java/org/hibernate/dialect/Database.java

@@ -231,7 +231,7 @@ public Dialect createDialect(DialectResolutionInfo info) {
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
-			return databaseName.startsWith( "Google Cloud Spanner" );
+			return databaseName.equals( "Google Cloud Spanner" );
 		}
 		@Override
 		public String getDriverClassName(String jdbcUrl) {