[Hibernate-issues] [Hibernate-JIRA] Created: (ANN-352) Incorrect database sceme created, when using multiple n:m relations between 2 entities

[Erik T. (JIRA) <no...@at...>]

Incorrect database sceme created, when using multiple n:m relations between=
 2 entities
---------------------------------------------------------------------------=
-----------

         Key: ANN-352
         URL: http://opensource.atlassian.com/projects/hibernate/browse/ANN=
-352
     Project: Hibernate Annotations
        Type: Bug

    Versions: 3.2.0.cr1   =20
 Environment: Linux, Java 1.5, Postgresql 8.0
    Reporter: Erik Tews


Hi

I got 2 entities:

@Entity
public class UserBean implements Serializable {
....
@ManyToMany
    protected Set<LectureBean> getAdminLectures() {
....
@ManyToMany
    protected Set<LectureBean> getLectures() {
.... }

and on the other side

@Entity=20
public class LectureBean implements Serializable {
@ManyToMany(mappedBy=3D"adminLectures", fetch=3DFetchType.LAZY, cascade=3DC=
ascadeType.PERSIST)
protected Set<UserBean> getAdminUsers() {
@ManyToMany(mappedBy=3D"lectures", fetch=3DFetchType.LAZY, cascade=3DCascad=
eType.PERSIST)
protected Set<UserBean> getUsers() {
....
}

so there are 2 n:m relations between these entities. Hibernate generates th=
e following table:

adminusers_userid | adminlectures_lectureid | users_userid | lectures_lectu=
reid

so it puts these 2 relations in one table but it adds foreign keys:

    =C2=BBfk3fb6262a62053223=C2=AB FOREIGN KEY (adminlectures_lectureid) RE=
FERENCES lecturebean(lectureid)
    =C2=BBfk3fb6262a569b3581=C2=AB FOREIGN KEY (users_userid) REFERENCES us=
erbean(userid)
    =C2=BBfk3fb6262afb45c494=C2=AB FOREIGN KEY (lectures_lectureid) REFEREN=
CES lecturebean(lectureid)
    =C2=BBfk3fb6262a66a3ba50=C2=AB FOREIGN KEY (adminusers_userid) REFERENC=
ES userbean(userid)

This makes it impossible to put 2 entities in relation, because 2 of the 4 =
columns will always be null.

Adding differen column names for the join tables with @JoinTable works arou=
nd the problem.

--=20
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