[hibernate-issues] [Hibernate-JIRA] Created: (EJB-315) unnecessary update when merge managed entity

unnecessary update when merge managed entity -------------------------------------------- Key: EJB-315 URL: http://opensource.atlassian.com/projects/hibernate/browse/EJB-315 Project: Hibernate Entity Manager Issue Type: Bug Affects Versions: 3.3.1.GA Environment: Hibernate Core 3.2.5.ga Hibernate Annotations 3.3.0 GA hsqldb Reporter: Jifeng Liu Attachments: testcase.zip If the entity in em.merge(entity) is managed entity, the merge operation should be ignored. However it issues a update statement in the test case even if there is no changes. In the test case, Parent entity has a list of Image entity with Many-To-Many relation. em.merge() somehow marks the list as dirty, which causes the update statement. The following is trace log of the test case. 07.20,23 INFO ASTQueryTranslatorFactory - Using ASTQueryTranslatorFactory 07.20,601 DEBUG SQL - /* insert test.Parent */ insert into Parent (updateDateTime, Parent_No) values (?, ?) 07.20,617 DEBUG SQL - /* insert test.Image */ insert into Image (name, imageNo) values (?, ?) 07.20,617 DEBUG SQL - /* insert collection row test.Parent.images */ insert into Parent_Image (Parent_Parent_No, images_ imageNo) values (?, ?) 07.20,632 DEBUG SQL - /* load test.Parent */ select parent0_.Parent_No as Parent1_0_0_, parent0_.updateDateTime as updat eDa2_0_0_ from Parent parent0_ where parent0_.Parent_No=? 07.20,648 DEBUG SQL - /* load collection test.Parent.images */ select images0_.Parent_Parent_No as Parent1_1_, images0_. images_imageNo as images2_1_, image1_.imageNo as imageNo1_0_, image1_.name as name1_0_ from Parent_Image images0_ left o uter join Image image1_ on images0_.images_imageNo=image1_.imageNo where images0_.Parent_Parent_No=? 07.20,679 DEBUG SQL - /* update test.Parent */ update Parent set updateDateTime=? where Parent_No=? and updateDateTime=? 07.20,679 DEBUG SQL - /* delete collection test.Parent.images */ delete from Parent_Image where Parent_Parent_No=? 07.20,679 DEBUG SQL - /* insert collection row test.Parent.images */ insert into Parent_Image (Parent_Parent_No, images_ imageNo) values (?, ?) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira