HHH-18855: Creation of a testcase

hibernate-core/src/test/java/org/hibernate/orm/test/fetch/GenerateSubselectsOnJoinedAssociationTest.java

@@ -0,0 +1,145 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.fetch;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinTable;
+import jakarta.persistence.ManyToMany;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+
+import org.hibernate.Hibernate;
+import org.hibernate.annotations.Fetch;
+import org.hibernate.annotations.FetchMode;
+import org.hibernate.engine.spi.BatchFetchQueue;
+import org.hibernate.engine.spi.EntityKey;
+import org.hibernate.engine.spi.SessionImplementor;
+import org.hibernate.persister.entity.EntityPersister;
+
+import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
+import org.hibernate.testing.orm.junit.Jpa;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+
+@Jpa(annotatedClasses = {
+		GenerateSubselectsOnJoinedAssociationTest.LazySelectRoot.class,
+		GenerateSubselectsOnJoinedAssociationTest.LazySelectNode.class
+})
+public class GenerateSubselectsOnJoinedAssociationTest {
+
+	@BeforeAll
+	static void setup(final EntityManagerFactoryScope scope) {
+		scope.inTransaction( em -> {
+			final LazySelectNode rootNode = new LazySelectNode();
+			rootNode.id = 10;
+
+			final LazySelectNode child1 = new LazySelectNode();
+			child1.id = 20;
+
+			final LazySelectNode child2 = new LazySelectNode();
+			child2.id = 30;
+
+			final LazySelectRoot root = new LazySelectRoot();
+			root.id = 1;
+
+			root.nodes.add( rootNode );
+			root.nodes.add( child1 );
+			root.nodes.add( child2 );
+			rootNode.root = root;
+			rootNode.children.add( child2 );
+			rootNode.children.add( child1 );
+			child1.root = root;
+			child2.root = root;
+
+			em.persist( root );
+		} );
+	}
+
+	@Test
+	void testSubselectFetchingFromFind(final EntityManagerFactoryScope scope) {
+		final LazySelectRoot root = scope.fromTransaction( em -> {
+			final SessionImplementor session = em.unwrap( SessionImplementor.class );
+			final EntityPersister persister = session.getEntityPersister( null, new LazySelectNode() );
+			final EntityKey key1 = session.generateEntityKey( 10, persister );
+			final EntityKey key2 = session.generateEntityKey( 20, persister );
+			final EntityKey key3 = session.generateEntityKey( 30, persister );
+
+			final LazySelectRoot in = em.find( LazySelectRoot.class, 1L );
+
+			final BatchFetchQueue batchFetchQueue = session.getPersistenceContextInternal().getBatchFetchQueue();
+			assertThat( batchFetchQueue.getSubselect( key1 ), is( notNullValue() ) );
+			assertThat( batchFetchQueue.getSubselect( key2 ), is( notNullValue() ) );
+			assertThat( batchFetchQueue.getSubselect( key3 ), is( notNullValue() ) );
+
+			return in;
+		} );
+
+		for ( final LazySelectNode node : root.nodes ) {
+			assertThat( Hibernate.isInitialized( ( (LazySelectNode) Hibernate.unproxy( node ) ).children ),
+						is( false )
+			);
+		}
+	}
+
+	@Test
+	void testSubselectFetchingFromQuery(final EntityManagerFactoryScope scope) {
+		final LazySelectRoot root = scope.fromTransaction( em -> {
+			final SessionImplementor session = em.unwrap( SessionImplementor.class );
+			final EntityPersister persister = session.getEntityPersister( null, new LazySelectNode() );
+			final EntityKey key1 = session.generateEntityKey( 10, persister );
+			final EntityKey key2 = session.generateEntityKey( 20, persister );
+			final EntityKey key3 = session.generateEntityKey( 30, persister );
+
+			final LazySelectRoot in = em.createQuery( "select r from root r join fetch r.nodes where r.id = ?1",
+													  LazySelectRoot.class ).setParameter( 1, 1 ).getSingleResult();
+
+			final BatchFetchQueue batchFetchQueue = session.getPersistenceContextInternal().getBatchFetchQueue();
+			assertThat( batchFetchQueue.getSubselect( key1 ), is( notNullValue() ) );
+			assertThat( batchFetchQueue.getSubselect( key2 ), is( notNullValue() ) );
+			assertThat( batchFetchQueue.getSubselect( key3 ), is( notNullValue() ) );
+			return in;
+		} );
+
+		for ( final LazySelectNode node : root.nodes ) {
+			assertThat( Hibernate.isInitialized( ( (LazySelectNode) Hibernate.unproxy( node ) ).children ),
+						is( false )
+			);
+		}
+	}
+
+	@Entity(name = "root")
+	public static class LazySelectRoot {
+		@Id
+		public Integer id;
+
+		@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "root")
+		public Set<LazySelectNode> nodes = new HashSet<>();
+	}
+
+	@Entity(name = "node")
+	public static class LazySelectNode {
+
+		@Id
+		public Integer id;
+
+		@ManyToOne(cascade = CascadeType.ALL)
+		public LazySelectRoot root;
+
+		@ManyToMany(cascade = CascadeType.ALL)
+		@JoinTable(name = "RELATIONSHIPS")
+		@Fetch(FetchMode.SUBSELECT)
+		public final Set<LazySelectNode> children = new HashSet<>();
+	}
+}