I am working on an web application running on GlassFish 4.1.1, using EclipseLink 2.6.1. I have a unidirectional ManyToMany relationship between Users and Projects, and when I remove elements from User.projects and merge the User, the join rows are not removed in the database. I made a smaller demo app to isolate it:
User class:
@Entity
@Table(name = "demouser")
public class DemoUser implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "DemoUserSeq")
@SequenceGenerator(name = "DemoUserSeq", sequenceName = "demouser_userid_seq", allocationSize = 1)
@Column(name = "userid")
private Integer id;
@Column(name = "username")
private String userName;
// some more fields
@JoinTable(name = "demouserprojbind", joinColumns = {
@JoinColumn(name = "username", referencedColumnName = "username")
}, inverseJoinColumns = {
@JoinColumn(name = "projcode", referencedColumnName = "projcode")
})
@ManyToMany
private Set<DemoProject> projects;
DemProject does NOT have a mapped ManyToMany to Users. The binding table "demouserprojbind" binds with unique (not-null) text columns instead of the serial PKs.
Demo update code:
DemoUser user = getUser(username); // EntityManager Query by username
Set<DemoProject> userProjects = user.getProjects();
userProjects.clear();
EntityManager em = emf.createEntityManager();
utx.begin();
em.joinTransaction();
em.merge(user);
em.flush();
utx.commit();
em.close();
This is demo code made in a Servlet - emf and utx and injected EntityManagerFactory and UserTransaction.
When I trace the SQL from EclipseLink, it looks like this:
DELETE FROM demouserprojbind WHERE ((projcode = ?) AND (username = ?))
bind => [Project2, null]
DELETE FROM demouserprojbind WHERE ((projcode = ?) AND (username = ?))
bind => [Project1, null]
It is apparently unable to put in the username of the owning entity - the SQL matches no rows, and thus no rows are deleted from the database.
Is there anything I do wrong in my save logic (I want to delete the binding between a User and a Project, but both the User and Project themselves should remain), or is it a bug in EcliseLink?
