Hello,

I want to implement a many-to-many relationship.

Like I have a User object and a UserGroup object. Both has many-to -many relation. Now what did I do:

Made a java class for User, with a setter for UserGroups as set
Made a java class for UserGroup

give mapping for UserGroups set in User mapping file like :

<set name="UserGroups" table="User_Groups" cascade="all" inverse="true" lazy="true">
<key column="User_id"/>
<many-to-many class="com.a.b.UserGroup">
<column name="UserGroup_Id"/>
</many-to-many>
</set>

Now, I made new objects of User and Set userGroups object to this object. I saved it.

As a result, I got records in User table and as well as in UserGroup table, but there I found no record in User_Groups table. I was expecting it, as relation table should be filled by itself by hibernate.

Am I wrong in this scenerio, Please guid me for it. It is urgent

Thanks,

I have the same problem.

even if the inverse thing is set correctly and the many-to-many is bidrectional ( with one inverse=true, and one inverse=false ) it simply wont add entries to the collection table (aka the mapping table).

I even have a one-to-one copy of the example from chapter 18 ( the one with the works and authors: http://www.hibernate.org/hib_docs/refer ... mples.html ) - it simply does not work.

is there anything special, in version 2.1?

please help!
-- Jakob

(1) Did you add objects to both sides of the association?
(2) Did you flush the session?



Please express yourself better in future, of course it works, you are using it wrong.

(1) Did you add objects to both sides of the association?
(2) Did you flush the session?



Please express yourself better in future, of course it works, you are using it wrong.

Jakob,

<set name="categories" table="catalog_category" cascade="all-delete-orphan" lazy="true">
<key column="catalog_id"/>
<many-to-many class="com.aceva.rms.catalog.Category">
<column name="category_id"/>
</many-to-many>
</set>

This mapping is working fine.

Gavin,

Thanks, and will try to explain problems in some better way.