[hibernate-issues] [Hibernate-JIRA] Issue Comment Edited: (HHH-5694) Unique constraint violation when removing an item from a unidirectional OneToMany ordered List

Unique constraint violation when removing an item from a unidirectional OneToMany ordered List ---------------------------------------------------------------------------------------------- Key: HHH-5694 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-5694 Project: Hibernate Core Issue Type: Bug Components: entity-manager Affects Versions: 3.5.0-Final, 3.5.1, 3.5.2, 3.5.3, 3.5.4, 3.5.5, 3.5.6, 3.6.0 Environment: Tested with Hibernate 3.5+ on H2, Derby, HSQLDB Reporter: Pascal Thivent Attachments: HHH-5694.zip, HHH-5694.zip I have a {{Foo}} entity that has a unidirectional ordered {{OneToMany}} {{List}} of {{Bars}}: {code} @Entity public class Foo { @Id @GeneratedValue private Long id; @OneToMany @OrderColumn(name = "order_index") @JoinTable(name = "foo_bar_map", joinColumns = @JoinColumn(name = "foo_id"), inverseJoinColumns = @JoinColumn(name = "bar_id")) private List<Bar> bars; //... } {code} So let's say {{Foo#1}} holds a list with {{Bar#1}}, {{Bar#2}}, {{Bar#3}} (in that order). When removing {{Bar#1}} from the List and persisting [[Foo#1}}, Hibernate performs the following weird SQL: {code} delete from foo_bar_map where foo_id=1 and order_index=2 update foo_bar_map set bar_id=2 where foo_id=1 and order_index=0 {code} And this obviously fails with a unique constraint violation. Why does Hibernate delete the last item from the join table? Why does Hibernate mess with the bar_id? Shouldn't Hibernate update the order_column instead? I'm attaching a mavenized test allowing to reproduce, run {{mvn test}}. FWIW, this works with the RI (run {{mvn test -Peclipselink,h2}}).