> 1)
> What is the best practive of managing additional
> columns in the JoinTable of ManyToMany relationships
> entities.
>
> I assume I can create another entity such as
> UserGroup for that, but maintanance grows that way
> since I need extra columsn in JoinTables in many
> places...
Some providers might provide an extended functionality, where a relationship with additional attributes can be mapped as java.util.Map. The key would be the related object, and the value an Object[] of the attribute values.
This is *extendend* functionality, making your application non-portable.
> 2) If one of the 'User' or 'Group' objects being
> removed, the relationship remains. is there any way
> to automatically remove the relationship? I do not
> want to remove the connected -objects-, only the
> relationships when one of the sides being removed.
This is dependent on the persistence provider, too. The portable way is to remove the relationships manually.
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