HHH-19669 hql insert fails for entity with join inheritance on Oracle

hibernate-core/src/main/java/org/hibernate/query/sqm/mutation/internal/cte/CteInsertHandler.java

@@ -702,7 +702,7 @@ protected String addDmlCtes(
 
 		final Generator identifierGenerator = entityDescriptor.getEntityPersister().getGenerator();
 		final List<Map.Entry<List<CteColumn>, Assignment>> tableAssignments = assignmentsByTable.get( rootTableReference );
-		if ( ( tableAssignments == null || tableAssignments.isEmpty() )
+		if ( !assignsId && ( tableAssignments == null || tableAssignments.isEmpty() )
 				&& !identifierGenerator.generatedOnExecution() ) {
 			throw new IllegalStateException( "There must be at least a single root table assignment" );
 		}

hibernate-core/src/main/java/org/hibernate/query/sqm/mutation/internal/temptable/InsertExecutionDelegate.java

@@ -217,7 +217,7 @@ public int execute(ExecutionContext executionContext) {
 			);
 
 			if ( rows != 0 ) {
-				final EntityPersister persister = entityDescriptor.getEntityPersister();
+				final EntityPersister 	persister = entityDescriptor.getEntityPersister();
 				final int tableSpan = persister.getTableSpan();
 				final int insertedRows = insertRootTable(
 						persister.getTableName( 0 ),
@@ -316,10 +316,11 @@ private int insertRootTable(
 		final EntityPersister entityPersister = entityDescriptor.getEntityPersister();
 		final Generator generator = entityPersister.getGenerator();
 		final List<Assignment> assignments = assignmentsByTable.get( tableExpression );
-		if ( ( assignments == null || assignments.isEmpty() )
-				&& !generator.generatedOnExecution()
-				&& ( !( generator instanceof BulkInsertionCapableIdentifierGenerator )
-					|| ( (BulkInsertionCapableIdentifierGenerator) generator ).supportsBulkInsertionIdentifierGeneration() ) ) {
+		if ( !assignsId
+			&& (assignments == null || assignments.isEmpty())
+			&& !generator.generatedOnExecution()
+			&& (!(generator instanceof BulkInsertionCapableIdentifierGenerator)
+				|| ((BulkInsertionCapableIdentifierGenerator) generator).supportsBulkInsertionIdentifierGeneration()) ) {
 			throw new IllegalStateException( "There must be at least a single root table assignment" );
 		}
 

hibernate-core/src/test/java/org/hibernate/orm/test/hql/JoinInheritanceInsertTest.java

@@ -0,0 +1,120 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.hql;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Inheritance;
+import jakarta.persistence.InheritanceType;
+import jakarta.persistence.Table;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.Jira;
+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.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DomainModel(
+		annotatedClasses = {
+				JoinInheritanceInsertTest.Book.class,
+				JoinInheritanceInsertTest.SpellBook.class
+		}
+)
+@SessionFactory
+@Jira( "HHH-19669" )
+public class JoinInheritanceInsertTest {
+
+	@AfterEach
+	public void tearDown(SessionFactoryScope scope) {
+		scope.getSessionFactory().getSchemaManager().truncateMappedObjects();
+	}
+
+	@Test
+	public void testInsertNoRootFieldsExceptForTheId(SessionFactoryScope scope) {
+		Integer id = 1;
+		scope.inTransaction( session -> {
+			session.createMutationQuery( "insert into SpellBook (id, forbidden) values (:id, :forbidden)" )
+					.setParameter( "id", id )
+					.setParameter( "forbidden", true )
+					.executeUpdate();
+		} );
+
+		scope.inTransaction( session -> {
+			SpellBook spellBook = session.find( SpellBook.class, id );
+			assertThat( spellBook ).isNotNull();
+			assertThat( spellBook.getForbidden() ).isTrue();
+			assertThat( spellBook.getTitle() ).isNull();
+		} );
+	}
+
+	@Test
+	public void testInsert2(SessionFactoryScope scope) {
+		Integer id = 1;
+		String title = "Spell Book: A Comprehensive Guide to Magic Spells and Incantations";
+
+		scope.inTransaction( session -> {
+			session.createMutationQuery( "insert into SpellBook (id, title, forbidden) values (:id, :title, :forbidden)" )
+					.setParameter( "id", id )
+					.setParameter( "title", title )
+					.setParameter( "forbidden", true )
+					.executeUpdate();
+		} );
+
+		scope.inTransaction( session -> {
+			SpellBook spellBook = session.find( SpellBook.class, id );
+			assertThat( spellBook ).isNotNull();
+			assertThat( spellBook.getTitle() ).isEqualTo( title );
+			assertThat( spellBook.getForbidden() ).isTrue();
+		} );
+	}
+
+	@Entity(name = "Book")
+	@Table(name = "BookJS")
+	@Inheritance(strategy = InheritanceType.JOINED)
+	public static class Book {
+
+		@Id
+		private Integer id;
+
+		private String title;
+
+		public Book() {
+		}
+
+		public Book(Integer id, String title) {
+			this.id = id;
+			this.title = title;
+		}
+
+		public Integer getId() {
+			return id;
+		}
+
+		public String getTitle() {
+			return title;
+		}
+	}
+
+	@Entity(name = "SpellBook")
+	@Table(name = "SpellBookJS")
+	public static class SpellBook extends Book {
+
+		private boolean forbidden;
+
+		SpellBook() {
+		}
+
+		public SpellBook(Integer id, String title, boolean forbidden) {
+			super( id, title );
+			this.forbidden = forbidden;
+		}
+
+		public boolean getForbidden() {
+			return forbidden;
+		}
+	}
+}