Fix treat join issue with one-to-many and make sure table pruning always works. Also fix some issues with union subclass pruning

Author: beikov

hibernate-core/src/main/java/org/hibernate/dialect/H2SqlAstTranslator.java

@@ -8,7 +8,9 @@
 
 import java.util.List;
 
+import org.hibernate.LockMode;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.internal.util.collections.CollectionHelper;
 import org.hibernate.query.sqm.ComparisonOperator;
 import org.hibernate.sql.ast.SqlAstNodeRenderingMode;
 import org.hibernate.sql.ast.spi.AbstractSqlAstTranslator;
@@ -21,6 +23,11 @@
 import org.hibernate.sql.ast.tree.expression.SqlTuple;
 import org.hibernate.sql.ast.tree.expression.SqlTupleContainer;
 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.from.QueryPartTableReference;
+import org.hibernate.sql.ast.tree.from.TableGroup;
+import org.hibernate.sql.ast.tree.from.TableReference;
 import org.hibernate.sql.ast.tree.predicate.BooleanExpressionPredicate;
 import org.hibernate.sql.ast.tree.predicate.InSubQueryPredicate;
 import org.hibernate.sql.ast.tree.select.QueryPart;
@@ -156,6 +163,23 @@ public void visitBinaryArithmeticExpression(BinaryArithmeticExpression arithmeti
 		appendSql( CLOSE_PARENTHESIS );
 	}
 
+	@Override
+	protected boolean renderPrimaryTableReference(TableGroup tableGroup, LockMode lockMode) {
+		final TableReference tableRef = tableGroup.getPrimaryTableReference();
+		// The H2 parser can't handle a sub-query as first element in a nested join
+		// i.e. `join ( (select ...) alias join ... )`, so we have to introduce a dummy table reference
+		if ( tableRef instanceof QueryPartTableReference || tableRef.getTableId().startsWith( "(select" ) ) {
+			final boolean realTableGroup = tableGroup.isRealTableGroup()
+					&& ( CollectionHelper.isNotEmpty( tableGroup.getTableReferenceJoins() )
+					|| hasNestedTableGroupsToRender( tableGroup.getNestedTableGroupJoins() ) );
+			if ( realTableGroup ) {
+				appendSql( "dual cross join " );
+			}
+		}
+		return super.renderPrimaryTableReference( tableGroup, lockMode );
+
+	}
+
 	@Override
 	protected boolean supportsRowValueConstructorSyntax() {
 		// Just a guess

hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

@@ -6497,11 +6497,6 @@ public void visitSubTypeAttributeMappings(Consumer<? super AttributeMapping> act
 		}
 	}
 
-	protected EntityMappingType getSubclassMappingType(String subclassName) {
-		return subclassMappingTypes != null ? subclassMappingTypes.get( subclassName ) : null;
-	}
-
-
 	// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 	// EntityDefinition impl (walking model - deprecated)
 

hibernate-core/src/main/java/org/hibernate/persister/entity/JoinedSubclassEntityPersister.java

@@ -48,6 +48,7 @@
 import org.hibernate.metamodel.mapping.internal.CaseStatementDiscriminatorMappingImpl;
 import org.hibernate.metamodel.mapping.internal.MappingModelCreationHelper;
 import org.hibernate.metamodel.mapping.internal.MappingModelCreationProcess;
+import org.hibernate.metamodel.spi.MappingMetamodelImplementor;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
 import org.hibernate.persister.spi.PersisterCreationContext;
 import org.hibernate.query.spi.NavigablePath;
@@ -1214,16 +1215,13 @@ public <T> DomainResult<T> createDomainResult(
 
 	@Override
 	public void pruneForSubclasses(TableGroup tableGroup, Set<String> treatedEntityNames) {
-		// If the base type is part of the treatedEntityNames this means we can't optimize this,
-		// as the table group is e.g. returned through a select
-		if ( treatedEntityNames.contains( getEntityName() ) ) {
-			return;
-		}
 		final Set<TableReference> retainedTableReferences = new HashSet<>( treatedEntityNames.size() );
 		final Set<String> sharedSuperclassTables = new HashSet<>();
+		final MappingMetamodelImplementor metamodel = getFactory().getRuntimeMetamodels().getMappingMetamodel();
 
 		for ( String treatedEntityName : treatedEntityNames ) {
-			final JoinedSubclassEntityPersister subPersister = (JoinedSubclassEntityPersister) getSubclassMappingType( treatedEntityName );
+			final JoinedSubclassEntityPersister subPersister =
+					(JoinedSubclassEntityPersister) metamodel.findEntityDescriptor( treatedEntityName );
 			final String[] subclassTableNames = subPersister.getSubclassTableNames();
 			// For every treated entity name, we collect table names that are needed by all treated entity names
 			// In mathematical terms, sharedSuperclassTables will be the "intersection" of the table names of all treated entities

hibernate-core/src/main/java/org/hibernate/persister/entity/SingleTableEntityPersister.java

@@ -880,11 +880,6 @@ else if ( discriminatorValue == DiscriminatorHelper.NOT_NULL_DISCRIMINATOR ) {
 
 	@Override
 	public void pruneForSubclasses(TableGroup tableGroup, Set<String> treatedEntityNames) {
-		// If the base type is part of the treatedEntityNames this means we can't optimize this,
-		// as the table group is e.g. returned through a select
-		if ( treatedEntityNames.contains( getEntityName() ) ) {
-			return;
-		}
 		// The optimization is to simply add the discriminator filter fragment for all treated entity names
 		final NamedTableReference tableReference = (NamedTableReference) tableGroup.getPrimaryTableReference();
 		tableReference.setPrunedTableExpression(

hibernate-core/src/main/java/org/hibernate/persister/entity/UnionSubclassEntityPersister.java

@@ -40,8 +40,10 @@
 import org.hibernate.mapping.Subclass;
 import org.hibernate.mapping.Table;
 import org.hibernate.metamodel.mapping.EntityDiscriminatorMapping;
+import org.hibernate.metamodel.mapping.SelectableConsumer;
 import org.hibernate.metamodel.mapping.SelectableMapping;
 import org.hibernate.metamodel.mapping.internal.MappingModelCreationProcess;
+import org.hibernate.metamodel.spi.MappingMetamodelImplementor;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
 import org.hibernate.persister.spi.PersisterCreationContext;
 import org.hibernate.query.spi.NavigablePath;
@@ -382,11 +384,6 @@ protected boolean hasMultipleTables() {
 
 	@Override
 	public void pruneForSubclasses(TableGroup tableGroup, Set<String> treatedEntityNames) {
-		// If the base type is part of the treatedEntityNames this means we can't optimize this,
-		// as the table group is e.g. returned through a select
-		if ( treatedEntityNames.contains( getEntityName() ) ) {
-			return;
-		}
 		final NamedTableReference tableReference = (NamedTableReference) tableGroup.resolveTableReference( getRootTableName() );
 		// Replace the default union sub-query with a specially created one that only selects the tables for the treated entity names
 		tableReference.setPrunedTableExpression( generateSubquery( treatedEntityNames ) );
@@ -496,33 +493,40 @@ protected String generateSubquery(Set<String> treated) {
 		}
 
 		final Dialect dialect = getFactory().getJdbcServices().getDialect();
+		final MappingMetamodelImplementor metamodel = getFactory().getRuntimeMetamodels().getMappingMetamodel();
 
 		// Collect all selectables of every entity subtype and group by selection expression as well as table name
 		final LinkedHashMap<String, Map<String, SelectableMapping>> selectables = new LinkedHashMap<>();
-		visitSubTypeAttributeMappings(
-				attributeMapping -> attributeMapping.forEachSelectable(
-						(i, selectable) -> selectables.computeIfAbsent( selectable.getSelectionExpression(), k -> new HashMap<>() )
-								.put( selectable.getContainingTableExpression(), selectable )
-				)
-		);
+		final SelectableConsumer selectableConsumer = (i, selectable) -> {
+			selectables.computeIfAbsent( selectable.getSelectionExpression(), k -> new HashMap<>() )
+					.put( selectable.getContainingTableExpression(), selectable );
+		};
 		// Collect the concrete subclass table names for the treated entity names
 		final Set<String> treatedTableNames = new HashSet<>( treated.size() );
 		for ( String subclassName : treated ) {
 			final UnionSubclassEntityPersister subPersister =
-					(UnionSubclassEntityPersister) getSubclassMappingType( subclassName );
+					(UnionSubclassEntityPersister) metamodel.getEntityDescriptor( subclassName );
 			for ( String subclassTableName : subPersister.getSubclassTableNames() ) {
 				if ( ArrayHelper.indexOf( subclassSpaces, subclassTableName ) != -1 ) {
 					treatedTableNames.add( subclassTableName );
 				}
 			}
+			subPersister.getIdentifierMapping().forEachSelectable( selectableConsumer );
+			if ( subPersister.getVersionMapping() != null ) {
+				subPersister.getVersionMapping().forEachSelectable( selectableConsumer );
+			}
+			subPersister.visitSubTypeAttributeMappings(
+					attributeMapping -> attributeMapping.forEachSelectable( selectableConsumer )
+			);
 		}
 
 		// Create a union sub-query for the table names, like generateSubquery(PersistentClass model, Mapping mapping)
 		final StringBuilder buf = new StringBuilder( subquery.length() )
 				.append( "( " );
 
-		for ( int i = 0; i < subclassTableNames.length; i++ ) {
-			final String subclassTableName = subclassTableNames[i];
+		for ( String name : getEntityMetamodel().getSubclassEntityNames() ) {
+			final AbstractEntityPersister persister = (AbstractEntityPersister) metamodel.findEntityDescriptor( name );
+			final String subclassTableName = persister.getTableName();
 			if ( treatedTableNames.contains( subclassTableName ) ) {
 				buf.append( "select " );
 				for ( Map<String, SelectableMapping> selectableMappings : selectables.values() ) {
@@ -540,7 +544,7 @@ protected String generateSubquery(Set<String> treated) {
 					);
 					buf.append( ", " );
 				}
-				buf.append( i ).append( " as clazz_" );
+				buf.append( persister.getDiscriminatorSQLValue() ).append( " as clazz_" );
 				buf.append( " from " ).append( subclassTableName );
 				buf.append( " union " );
 				if ( dialect.supportsUnionAll() ) {

hibernate-core/src/main/java/org/hibernate/query/sqm/function/SelfRenderingSqmAggregateFunction.java

@@ -21,7 +21,6 @@
 import org.hibernate.query.sqm.tree.predicate.SqmPredicate;
 import org.hibernate.query.sqm.tree.select.SqmSelectableNode;
 import org.hibernate.sql.ast.tree.SqlAstNode;
-import org.hibernate.sql.ast.tree.predicate.Predicate;
 
 /**
  * @author Christian Beikov
@@ -88,7 +87,7 @@ public SelfRenderingFunctionSqlAstExpression convertToSqlAst(SqmToSqlAstConverte
 				getFunctionName(),
 				getRenderingSupport(),
 				resolveSqlAstArguments( getArguments(), walker ),
-				filter == null ? null : (Predicate) filter.accept( walker ),
+				filter == null ? null : walker.visitNestedTopLevelPredicate( filter ),
 				resultType,
 				getMappingModelExpressible( walker, resultType )
 		);