HHH-15328 Add support for CTE WITH clause

Author: beikov

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

@@ -37,16 +37,6 @@ public void visitOffsetFetchClause(QueryPart queryPart) {
 		renderCombinedLimitClause( queryPart );
 	}
 
-	@Override
-	protected void renderSearchClause(CteStatement cte) {
-		// CUBRID does not support this, but it's just a hint anyway
-	}
-
-	@Override
-	protected void renderCycleClause(CteStatement cte) {
-		// CUBRID does not support this, but it can be emulated
-	}
-
 	@Override
 	protected void renderComparison(Expression lhs, ComparisonOperator operator, Expression rhs) {
 		renderComparisonEmulateIntersect( lhs, operator, rhs );

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

@@ -80,16 +80,6 @@ public void visitOffsetFetchClause(QueryPart queryPart) {
 		}
 	}
 
-	@Override
-	protected void renderSearchClause(CteStatement cte) {
-		// Cache does not support this, but it's just a hint anyway
-	}
-
-	@Override
-	protected void renderCycleClause(CteStatement cte) {
-		// Cache does not support this, but it can be emulated
-	}
-
 	@Override
 	protected void renderComparison(Expression lhs, ComparisonOperator operator, Expression rhs) {
 		renderComparisonEmulateIntersect( lhs, operator, rhs );

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

@@ -468,6 +468,11 @@ public boolean supportsNonQueryWithCTE() {
 		return true;
 	}
 
+	@Override
+	public boolean supportsRecursiveCTE() {
+		return getVersion().isSameOrAfter( 20, 1 );
+	}
+
 	@Override
 	public String getNoColumnsInsertString() {
 		return "default values";

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

@@ -9,6 +9,7 @@
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.sql.ast.spi.AbstractSqlAstTranslator;
 import org.hibernate.sql.ast.tree.Statement;
+import org.hibernate.sql.ast.tree.cte.CteMaterialization;
 import org.hibernate.sql.ast.tree.cte.CteStatement;
 import org.hibernate.sql.ast.tree.expression.Expression;
 import org.hibernate.sql.ast.tree.expression.Literal;
@@ -52,6 +53,26 @@ public void visitBooleanExpressionPredicate(BooleanExpressionPredicate booleanEx
 		}
 	}
 
+	@Override
+	protected void renderMaterializationHint(CteMaterialization materialization) {
+		if ( getDialect().getVersion().isSameOrAfter( 20, 2 ) ) {
+			if ( materialization == CteMaterialization.NOT_MATERIALIZED ) {
+				appendSql( "not " );
+			}
+			appendSql( "materialized " );
+		}
+	}
+
+	@Override
+	protected boolean supportsRowConstructor() {
+		return true;
+	}
+
+	@Override
+	protected boolean supportsArrayConstructor() {
+		return true;
+	}
+
 	@Override
 	protected String getForShare(int timeoutMillis) {
 		return " for share";
@@ -116,16 +137,6 @@ public void visitOffsetFetchClause(QueryPart queryPart) {
 		}
 	}
 
-	@Override
-	protected void renderSearchClause(CteStatement cte) {
-		// Cockroach does not support this, but it's just a hint anyway
-	}
-
-	@Override
-	protected void renderCycleClause(CteStatement cte) {
-		// Cockroach does not support this, but it can be emulated
-	}
-
 	@Override
 	protected void renderPartitionItem(Expression expression) {
 		if ( expression instanceof Literal ) {

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2LegacyDialect.java

@@ -534,6 +534,11 @@ public boolean supportsLockTimeouts() {
 		return false;
 	}
 
+	@Override
+	public boolean requiresCastForConcatenatingNonStrings() {
+		return true;
+	}
+
 	@Override
 	public String getSelectClauseNullString(int sqlType, TypeConfiguration typeConfiguration) {
 		return selectNullString(sqlType);
@@ -756,6 +761,12 @@ public boolean supportsNonQueryWithCTE() {
 		return true;
 	}
 
+	@Override
+	public boolean supportsRecursiveCTE() {
+		// Supported at last since 9.7
+		return getDB2Version().isSameOrAfter( 9, 7 );
+	}
+
 	@Override
 	public boolean supportsOffsetInSubquery() {
 		return true;

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2LegacySqlAstTranslator.java

@@ -9,6 +9,7 @@
 import java.util.List;
 import java.util.function.Consumer;
 
+import org.hibernate.LockMode;
 import org.hibernate.dialect.DatabaseVersion;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.query.sqm.ComparisonOperator;
@@ -26,6 +27,9 @@
 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.TableGroup;
+import org.hibernate.sql.ast.tree.from.TableGroupJoin;
+import org.hibernate.sql.ast.tree.from.TableReferenceJoin;
 import org.hibernate.sql.ast.tree.insert.InsertStatement;
 import org.hibernate.sql.ast.tree.predicate.BooleanExpressionPredicate;
 import org.hibernate.sql.ast.tree.select.QueryGroup;
@@ -45,6 +49,70 @@ public DB2LegacySqlAstTranslator(SessionFactoryImplementor sessionFactory, State
 		super( sessionFactory, statement );
 	}
 
+	@Override
+	protected boolean needsRecursiveKeywordInWithClause() {
+		return false;
+	}
+
+	@Override
+	protected boolean supportsWithClauseInSubquery() {
+		return false;
+	}
+
+	@Override
+	protected void renderTableReferenceJoins(TableGroup tableGroup) {
+		// When we are in a recursive CTE, we can't render joins on DB2...
+		// See https://modern-sql.com/feature/with-recursive/db2/error-345-state-42836
+		if ( isInRecursiveQueryPart() ) {
+			final List<TableReferenceJoin> joins = tableGroup.getTableReferenceJoins();
+			if ( joins == null || joins.isEmpty() ) {
+				return;
+			}
+
+			for ( TableReferenceJoin tableJoin : joins ) {
+				switch ( tableJoin.getJoinType() ) {
+					case CROSS:
+					case INNER:
+						break;
+					default:
+						throw new UnsupportedOperationException( "Can't emulate '" + tableJoin.getJoinType().getText() + "join' in a DB2 recursive query part" );
+				}
+				appendSql( COMA_SEPARATOR_CHAR );
+
+				renderNamedTableReference( tableJoin.getJoinedTableReference(), LockMode.NONE );
+
+				if ( tableJoin.getPredicate() != null && !tableJoin.getPredicate().isEmpty() ) {
+					addAdditionalWherePredicate( tableJoin.getPredicate() );
+				}
+			}
+		}
+		else {
+			super.renderTableReferenceJoins( tableGroup );
+		}
+	}
+
+	@Override
+	protected void renderTableGroupJoin(TableGroupJoin tableGroupJoin, List<TableGroupJoin> tableGroupJoinCollector) {
+		if ( isInRecursiveQueryPart() ) {
+			switch ( tableGroupJoin.getJoinType() ) {
+				case CROSS:
+				case INNER:
+					break;
+				default:
+					throw new UnsupportedOperationException( "Can't emulate '" + tableGroupJoin.getJoinType().getText() + "join' in a DB2 recursive query part" );
+			}
+			appendSql( COMA_SEPARATOR_CHAR );
+
+			renderTableGroup( tableGroupJoin.getJoinedGroup(), null, tableGroupJoinCollector );
+			if ( tableGroupJoin.getPredicate() != null && !tableGroupJoin.getPredicate().isEmpty() ) {
+				addAdditionalWherePredicate( tableGroupJoin.getPredicate() );
+			}
+		}
+		else {
+			super.renderTableGroupJoin( tableGroupJoin, tableGroupJoinCollector );
+		}
+	}
+
 	@Override
 	protected void renderExpressionAsClauseItem(Expression expression) {
 		expression.accept( this );

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2iLegacyDialect.java

@@ -123,6 +123,11 @@ public boolean supportsLateral() {
 		return getVersion().isSameOrAfter( 7, 1 );
 	}
 
+	@Override
+	public boolean supportsRecursiveCTE() {
+		return getVersion().isSameOrAfter( 7, 1 );
+	}
+
 	@Override
 	public SqlAstTranslatorFactory getSqlAstTranslatorFactory() {
 		return new StandardSqlAstTranslatorFactory() {

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2zLegacyDialect.java

@@ -125,6 +125,11 @@ public boolean supportsLateral() {
 		return true;
 	}
 
+	@Override
+	public boolean supportsRecursiveCTE() {
+		return getVersion().isSameOrAfter( 11 );
+	}
+
 	@Override
 	public String timestampaddPattern(TemporalUnit unit, TemporalType temporalType, IntervalType intervalType) {
 		StringBuilder pattern = new StringBuilder();

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2zLegacySqlAstTranslator.java

@@ -61,6 +61,10 @@ protected void renderComparison(Expression lhs, ComparisonOperator operator, Exp
 
 	@Override
 	protected boolean renderPrimaryTableReference(TableGroup tableGroup, LockMode lockMode) {
+		if ( shouldInlineCte( tableGroup ) ) {
+			inlineCteTableGroup( tableGroup, lockMode );
+			return false;
+		}
 		final TableReference tableReference = tableGroup.getPrimaryTableReference();
 		if ( tableReference instanceof NamedTableReference ) {
 			return renderNamedTableReference( (NamedTableReference) tableReference, lockMode );

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

@@ -18,6 +18,7 @@
 import org.hibernate.dialect.RowLockStrategy;
 import org.hibernate.dialect.function.CaseLeastGreatestEmulation;
 import org.hibernate.dialect.function.CastingConcatFunction;
+import org.hibernate.dialect.function.ChrLiteralEmulation;
 import org.hibernate.dialect.function.CommonFunctionFactory;
 import org.hibernate.dialect.function.CountFunction;
 import org.hibernate.dialect.function.DerbyLpadEmulation;
@@ -286,6 +287,16 @@ public void initializeFunctionRegistry(QueryEngine queryEngine) {
 		// AVG by default uses the input type, so we possibly need to cast the argument type, hence a special function
 		functionFactory.avg_castingNonDoubleArguments( this, SqlAstNodeRenderingMode.DEFAULT );
 
+		// Note that Derby does not have chr() / ascii() functions.
+		// It does have a function named char(), but it's really a
+		// sort of to_char() function.
+
+		// We register an emulation instead, that can at least translate integer literals
+		queryEngine.getSqmFunctionRegistry().register(
+				"chr",
+				new ChrLiteralEmulation( queryEngine.getTypeConfiguration() )
+		);
+
 		functionFactory.concat_pipeOperator();
 		functionFactory.cot();
 		functionFactory.chr_char();
@@ -604,6 +615,11 @@ public boolean supportsOrderByInSubquery() {
 		return getVersion().isSameOrAfter( 10, 5 );
 	}
 
+	@Override
+	public boolean requiresCastForConcatenatingNonStrings() {
+		return true;
+	}
+
 	@Override
 	public void contributeTypes(TypeContributions typeContributions, ServiceRegistry serviceRegistry) {
 		super.contributeTypes( typeContributions, serviceRegistry );