Hi,

I have a Groups table, which contains name and users id who has defined this group.

However, the same user can define one and only one group with the same name. This way I need to define a contstraint that combination of name and user_id should be unique i.e multiple entries with same name and user id should not be allowed.

i.e in groups table

name --> user id
family --> 10
family --> 11

should be allowed but not

family --> 10
family --> 10

should not be allowed.

Could any one tell me the way to use the annotations in group class so that such contrants are taken care. I appricate JPA approach if possible else hibernate specific approach is also fine.

Regards,
Raja Nagendra Kumar,
C.T.O
www.tejasoft.com

Hi,
Is name and group form the primary key of the entity. If so why not define a composite key for the table.

Nope application level key defination may be to heavy for this requirment.. I am hoping there would be a simpler way..

I have come across annotations like..

@Table(name = "TBL_GROUPS",
uniqueConstraints = {@UniqueConstraint(columnNames = {"name", "fk_user"})})


Regards,
Nagendra