HHH-19991: Provide some fixes for spanner dialect

Author: rayudu3745

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

@@ -8,6 +8,7 @@
 import jakarta.persistence.Timeout;
 import org.hibernate.LockMode;
 import org.hibernate.LockOptions;
+import org.hibernate.ScrollMode;
 import org.hibernate.StaleObjectStateException;
 import org.hibernate.boot.Metadata;
 import org.hibernate.boot.model.FunctionContributions;
@@ -25,6 +26,8 @@
 import org.hibernate.dialect.sql.ast.SpannerSqlAstTranslator;
 import org.hibernate.dialect.unique.UniqueDelegate;
 import org.hibernate.engine.jdbc.dialect.spi.DialectResolutionInfo;
+import org.hibernate.engine.jdbc.env.spi.IdentifierHelper;
+import org.hibernate.engine.jdbc.env.spi.IdentifierHelperBuilder;
 import org.hibernate.engine.jdbc.env.spi.SchemaNameResolver;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
@@ -50,6 +53,8 @@
 import org.hibernate.type.BasicTypeRegistry;
 import org.hibernate.type.StandardBasicTypes;
 
+import java.sql.DatabaseMetaData;
+import java.sql.SQLException;
 import java.util.Date;
 import java.util.Map;
 
@@ -502,6 +507,16 @@ public Exporter<Table> getTableExporter() {
 		return this.spannerTableExporter;
 	}
 
+	@Override
+	public String getCreateTableString() {
+		return "create table if not exists";
+	}
+
+	@Override
+	public boolean supportsIfExistsBeforeTableName() {
+		return true;
+	}
+
 	/* SELECT-related functions */
 
 	@Override
@@ -895,6 +910,32 @@ public boolean supportsRowValueConstructorSyntaxInInList() {
 		return false;
 	}
 
+	@Override
+	public DmlTargetColumnQualifierSupport getDmlTargetColumnQualifierSupport() {
+		return DmlTargetColumnQualifierSupport.TABLE_ALIAS;
+	}
+
+	@Override
+	public IdentifierHelper buildIdentifierHelper(
+			IdentifierHelperBuilder builder,
+			DatabaseMetaData metadata) throws SQLException {
+		builder.applyReservedWords( metadata );
+		builder.setAutoQuoteKeywords( true );
+		builder.setAutoQuoteDollar( true );
+		return super.buildIdentifierHelper( builder, metadata );
+	}
+
+	@Override
+	public ScrollMode defaultScrollMode() {
+		return ScrollMode.FORWARD_ONLY;
+	}
+
+	@Override
+	public String getTruncateTableStatement(String tableName) {
+		// spanner doesn't have truncate command, so we delete
+		return "delete from " + tableName + " where true";
+	}
+
 	/* Type conversion and casting */
 
 	/**

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

@@ -13,12 +13,14 @@
 import java.util.stream.StreamSupport;
 
 import org.hibernate.boot.Metadata;
+import org.hibernate.boot.model.relational.InitCommand;
 import org.hibernate.boot.model.relational.SqlStringGenerationContext;
 import org.hibernate.mapping.Column;
 import org.hibernate.mapping.Index;
 import org.hibernate.mapping.Table;
 import org.hibernate.tool.schema.spi.Exporter;
 
+import static java.util.Collections.addAll;
 import static org.hibernate.internal.util.collections.ArrayHelper.EMPTY_STRING_ARRAY;
 
 /**
@@ -67,7 +69,7 @@ else if ( !table.getForeignKeyCollection().isEmpty() ) {
 
 	private String[] getTableString(Table table, Metadata metadata, Iterable<Column> keyColumns, SqlStringGenerationContext context) {
 		String primaryKeyColNames = StreamSupport.stream( keyColumns.spliterator(), false )
-				.map( Column::getName )
+				.map( col -> col.getQuotedName( spannerDialect )  )
 				.collect( Collectors.joining( "," ) );
 
 		StringJoiner colsAndTypes = new StringJoiner( "," );
@@ -76,7 +78,7 @@ private String[] getTableString(Table table, Metadata metadata, Iterable<Column>
 		for ( Column column : table.getColumns() ) {
 			final String sqlType = column.getSqlType( metadata );
 			final String columnDeclaration =
-					column.getName()
+					column.getQuotedName(spannerDialect)
 							+ " " + sqlType
 							+ ( column.isNullable() ? this.spannerDialect.getNullColumnString( sqlType ) : " not null" );
 			colsAndTypes.add( columnDeclaration );
@@ -92,6 +94,10 @@ private String[] getTableString(Table table, Metadata metadata, Iterable<Column>
 				)
 		);
 
+		for ( InitCommand initCommand : table.getInitCommands( context ) ) {
+			addAll( statements, initCommand.initCommands() );
+		}
+
 		return statements.toArray(EMPTY_STRING_ARRAY);
 	}
 
@@ -106,7 +112,7 @@ public String[] getSqlDropStrings(Table table, Metadata metadata, SqlStringGener
 		ArrayList<String> dropStrings = new ArrayList<>();
 
 		for ( Index index : table.getIndexes().values() ) {
-			dropStrings.add( "drop index " + index.getName() );
+			dropStrings.add( "drop index if exists " + index.getName() );
 		}
 
 		dropStrings.add( this.spannerDialect.getDropTableString( context.format( table.getQualifiedTableName() ) ) );

hibernate-core/src/main/java/org/hibernate/dialect/sql/ast/SpannerSqlAstTranslator.java

@@ -13,14 +13,17 @@
 import org.hibernate.sql.ast.spi.AbstractSqlAstTranslator;
 import org.hibernate.sql.ast.spi.SqlSelection;
 import org.hibernate.sql.ast.tree.Statement;
+import org.hibernate.sql.ast.tree.delete.DeleteStatement;
 import org.hibernate.sql.ast.tree.expression.Expression;
 import org.hibernate.sql.ast.tree.expression.Literal;
 import org.hibernate.sql.ast.tree.expression.SqlTuple;
 import org.hibernate.sql.ast.tree.expression.Summarization;
 import org.hibernate.sql.ast.tree.from.DerivedTableReference;
+import org.hibernate.sql.ast.tree.from.NamedTableReference;
 import org.hibernate.sql.ast.tree.select.QueryPart;
 import org.hibernate.sql.ast.tree.select.QuerySpec;
 import org.hibernate.sql.ast.tree.select.SelectClause;
+import org.hibernate.sql.ast.tree.update.UpdateStatement;
 import org.hibernate.sql.exec.spi.JdbcOperation;
 
 /**
@@ -112,4 +115,37 @@ protected void renderDerivedTableReference(DerivedTableReference tableReference)
 		}
 	}
 
+	@Override
+	protected void visitDeleteStatementOnly(DeleteStatement statement) {
+		// Spanner requires a WHERE in delete clause so we add "where true" if there is none
+		if ( !hasWhere( statement.getRestriction() ) ) {
+			renderDeleteClause( statement );
+			appendSql( " where true" );
+			visitReturningColumns( statement.getReturningColumns() );
+		} else {
+			super.visitDeleteStatementOnly( statement );
+		}
+	}
+
+	@Override
+	protected void visitUpdateStatementOnly(UpdateStatement statement) {
+		// Spanner requires a WHERE in update clause so we add "where true" if there is none
+		if ( !hasWhere( statement.getRestriction() ) ) {
+			renderUpdateClause( statement );
+			renderSetClause( statement.getAssignments() );
+			appendSql( " where true" );
+			visitReturningColumns( statement.getReturningColumns() );
+		} else {
+			super.visitUpdateStatementOnly( statement );
+		}
+	}
+
+	@Override
+	protected void renderDmlTargetTableExpression(NamedTableReference tableReference) {
+		super.renderDmlTargetTableExpression( tableReference );
+		if ( getClauseStack().getCurrent() != Clause.INSERT ) {
+			renderTableReferenceIdentificationVariable( tableReference );
+		}
+	}
+
 }