HHH-15868 Added `crossJoin` methods and logic

hibernate-core/src/main/java/org/hibernate/query/criteria/JpaCrossJoin.java

@@ -0,0 +1,16 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.query.criteria;
+
+import org.hibernate.Incubating;
+
+/**
+ * @author Marco Belladelli
+ */
+@Incubating
+public interface JpaCrossJoin<T> extends JpaFrom<T, T> {
+}

hibernate-core/src/main/java/org/hibernate/query/criteria/JpaFrom.java

@@ -10,13 +10,8 @@ import org.hibernate.Incubating;
 import org.hibernate.metamodel.model.domain.EntityDomainType;
 import org.hibernate.query.sqm.tree.SqmJoinType;
 
-import jakarta.persistence.criteria.CollectionJoin;
 import jakarta.persistence.criteria.From;
-import jakarta.persistence.criteria.Join;
 import jakarta.persistence.criteria.JoinType;
-import jakarta.persistence.criteria.ListJoin;
-import jakarta.persistence.criteria.MapJoin;
-import jakarta.persistence.criteria.SetJoin;
 import jakarta.persistence.criteria.Subquery;
 import jakarta.persistence.metamodel.CollectionAttribute;
 import jakarta.persistence.metamodel.ListAttribute;
@@ -62,6 +57,12 @@ public interface JpaFrom<O,T> extends JpaPath<T>, JpaFetchParent<O,T>, From<O,T>
 	@Incubating
 	<X> JpaJoinedFrom<?, X> join(JpaCteCriteria<X> cte, SqmJoinType joinType);
 
+	@Incubating
+	<X> JpaCrossJoin<X> crossJoin(Class<X> entityJavaType);
+
+	@Incubating
+	<X> JpaCrossJoin<X> crossJoin(EntityDomainType<X> entity);
+
 	// Covariant overrides
 
 	@Override

hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/AbstractSqmFrom.java

@@ -24,6 +24,7 @@ import org.hibernate.metamodel.model.domain.MapPersistentAttribute;
 import org.hibernate.metamodel.model.domain.PluralPersistentAttribute;
 import org.hibernate.metamodel.model.domain.SetPersistentAttribute;
 import org.hibernate.metamodel.model.domain.SingularPersistentAttribute;
+import org.hibernate.query.criteria.JpaCrossJoin;
 import org.hibernate.query.criteria.JpaCteCriteria;
 import org.hibernate.query.criteria.JpaDerivedJoin;
 import org.hibernate.query.criteria.JpaJoinedFrom;
@@ -622,6 +623,19 @@ public abstract class AbstractSqmFrom<O,T> extends AbstractSqmPath<T> implements
 		}
 	}
 
+	@Override
+	public <X> JpaCrossJoin<X> crossJoin(Class<X> entityJavaType) {
+		return crossJoin( nodeBuilder().getDomainModel().entity( entityJavaType ) );
+	}
+
+	@Override
+	public <X> JpaCrossJoin<X> crossJoin(EntityDomainType<X> entity) {
+		final SqmCrossJoin<X> crossJoin = new SqmCrossJoin<>( entity, null, findRoot() );
+		// noinspection unchecked
+		addSqmJoin( (SqmJoin<T, ?>) crossJoin );
+		return crossJoin;
+	}
+
 	@Override
 	public Set<Fetch<T, ?>> getFetches() {
 		//noinspection unchecked

hibernate-core/src/main/java/org/hibernate/query/sqm/tree/from/SqmCrossJoin.java

@@ -7,6 +7,7 @@
 package org.hibernate.query.sqm.tree.from;
 
 import org.hibernate.metamodel.model.domain.EntityDomainType;
+import org.hibernate.query.criteria.JpaCrossJoin;
 import org.hibernate.spi.NavigablePath;
 import org.hibernate.query.PathException;
 import org.hibernate.query.hql.spi.SqmCreationProcessingState;
@@ -24,7 +25,7 @@ import static org.hibernate.query.sqm.spi.SqmCreationHelper.buildRootNavigablePa
 /**
  * @author Steve Ebersole
  */
-public class SqmCrossJoin<T> extends AbstractSqmFrom<T, T> implements SqmJoin<T, T> {
+public class SqmCrossJoin<T> extends AbstractSqmFrom<T, T> implements JpaCrossJoin<T>, SqmJoin<T, T> {
 	private final SqmRoot<?> sqmRoot;
 
 	public SqmCrossJoin(

hibernate-core/src/test/java/org/hibernate/orm/test/query/criteria/CriteriaCrossJoinTest.java

@@ -0,0 +1,110 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.orm.test.query.criteria;
+
+import java.time.LocalDateTime;
+import java.util.Date;
+import java.util.List;
+
+import org.hibernate.query.criteria.HibernateCriteriaBuilder;
+import org.hibernate.query.criteria.JpaCrossJoin;
+import org.hibernate.query.criteria.JpaRoot;
+
+import org.hibernate.testing.orm.domain.gambit.EntityOfBasics;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Tuple;
+import jakarta.persistence.criteria.CriteriaQuery;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * @author Marco Belladelli
+ */
+@DomainModel(annotatedClasses = EntityOfBasics.class)
+@SessionFactory
+public class CriteriaCrossJoinTest {
+
+	@BeforeEach
+	public void setUp(SessionFactoryScope scope) {
+		scope.inTransaction( em -> {
+			Date now = new Date();
+
+			EntityOfBasics entity1 = new EntityOfBasics();
+			entity1.setId( 1 );
+			entity1.setTheString( "5" );
+			entity1.setTheInt( 5 );
+			entity1.setTheInteger( -1 );
+			entity1.setTheDouble( 1.0 );
+			entity1.setTheDate( now );
+			entity1.setTheLocalDateTime( LocalDateTime.now() );
+			entity1.setTheBoolean( true );
+			em.persist( entity1 );
+
+			EntityOfBasics entity2 = new EntityOfBasics();
+			entity2.setId( 2 );
+			entity2.setTheString( "6" );
+			entity2.setTheInt( 6 );
+			entity2.setTheInteger( -2 );
+			entity2.setTheDouble( 6.0 );
+			entity2.setTheBoolean( true );
+			em.persist( entity2 );
+
+			EntityOfBasics entity3 = new EntityOfBasics();
+			entity3.setId( 3 );
+			entity3.setTheString( "7" );
+			entity3.setTheInt( 7 );
+			entity3.setTheInteger( 3 );
+			entity3.setTheDouble( 7.0 );
+			entity3.setTheBoolean( false );
+			entity3.setTheDate( new Date( now.getTime() + 200000L ) );
+			em.persist( entity3 );
+
+			EntityOfBasics entity4 = new EntityOfBasics();
+			entity4.setId( 4 );
+			entity4.setTheString( "thirteen" );
+			entity4.setTheInt( 13 );
+			entity4.setTheInteger( 4 );
+			entity4.setTheDouble( 13.0 );
+			entity4.setTheBoolean( false );
+			entity4.setTheDate( new Date( now.getTime() + 300000L ) );
+			em.persist( entity4 );
+
+			EntityOfBasics entity5 = new EntityOfBasics();
+			entity5.setId( 5 );
+			entity5.setTheString( "5" );
+			entity5.setTheInt( 5 );
+			entity5.setTheInteger( 5 );
+			entity5.setTheDouble( 9.0 );
+			entity5.setTheBoolean( false );
+			em.persist( entity5 );
+		} );
+	}
+
+	@AfterEach
+	public void tearDown(SessionFactoryScope scope) {
+		scope.inTransaction( session -> session.createMutationQuery( "delete from EntityOfBasics" ).executeUpdate() );
+	}
+
+	@Test
+	public void testSimpleCrossJoin(SessionFactoryScope scope) {
+		scope.inTransaction( session -> {
+			HibernateCriteriaBuilder cb = session.getCriteriaBuilder();
+			CriteriaQuery<Tuple> query = cb.createTupleQuery();
+			JpaRoot<EntityOfBasics> from = (JpaRoot<EntityOfBasics>) query.from( EntityOfBasics.class );
+			JpaCrossJoin<EntityOfBasics> crossJoin = from.crossJoin( EntityOfBasics.class );
+			query.multiselect( from.get( "id" ), crossJoin.get( "id" ) ).where( cb.gt( crossJoin.get( "theInt" ), 5 ) );
+			List<Tuple> resultList = session.createQuery( query ).getResultList();
+			assertEquals( 15, resultList.size() );
+		} );
+	}
+}

hibernate-core/src/test/java/org/hibernate/orm/test/query/criteria/CriteriaOrderedSetAggregateTest.java

@@ -15,7 +15,9 @@ import org.hibernate.dialect.H2Dialect;
 import org.hibernate.dialect.PostgreSQLDialect;
 import org.hibernate.dialect.PostgresPlusDialect;
 import org.hibernate.query.criteria.HibernateCriteriaBuilder;
+import org.hibernate.query.criteria.JpaCrossJoin;
 import org.hibernate.query.criteria.JpaExpression;
+import org.hibernate.query.criteria.JpaRoot;
 import org.hibernate.query.criteria.JpaWindow;
 import org.hibernate.query.sqm.NullPrecedence;
 import org.hibernate.query.sqm.SortOrder;
@@ -309,17 +311,16 @@ public class CriteriaOrderedSetAggregateTest {
 	@RequiresDialectFeature(feature = DialectFeatureChecks.SupportsHypotheticalSetFunctions.class)
 	@RequiresDialect(H2Dialect.class)
 	public void testHypotheticalSetRankWithGroupByHavingOrderByLimit(SessionFactoryScope scope) {
-		// note : cross joins are not supported in criteria and this query structure causes problems with many dbs
 		scope.inTransaction( session -> {
 			HibernateCriteriaBuilder cb = session.getCriteriaBuilder();
 			CriteriaQuery<Tuple> cr = cb.createQuery( Tuple.class );
-			Root<EntityOfBasics> root1 = cr.from( EntityOfBasics.class );
+			JpaRoot<EntityOfBasics> e1 = (JpaRoot<EntityOfBasics>) cr.from( EntityOfBasics.class );
-			Root<EntityOfBasics> root2 = cr.from( EntityOfBasics.class );
+			JpaCrossJoin<EntityOfBasics> e2 = e1.crossJoin( EntityOfBasics.class );
 
-			JpaExpression<Long> function = cb.rank( cb.asc( root1.get( "theInt" ) ), cb.literal( 5 ) );
+			JpaExpression<Long> function = cb.rank( cb.asc( e1.get( "theInt" ) ), cb.literal( 5 ) );
 
-			cr.multiselect( root2.get( "id" ), function )
+			cr.multiselect( e2.get( "id" ), function )
-					.groupBy( root2.get( "id" ) ).having( cb.gt( root2.get( "id" ), cb.literal( 1 ) ) )
+					.groupBy( e2.get( "id" ) ).having( cb.gt( e2.get( "id" ), cb.literal( 1 ) ) )
 					.orderBy( cb.asc( cb.literal( 1 ) ), cb.asc( cb.literal( 2 ) ) );
 
 			List<Tuple> resultList = session.createQuery( cr ).setFirstResult( 1 ).getResultList();