Unique Constraint Over Multiple Columns
hibernate, hibernate-mapping, postgresql, seam, seam2
Solution
There is no Hibernate annotation that checks uniqueness before insert/update. But there is annotation which will generate such a constraint to database if automatic database creation is used:
@Table(
name="ACTIVE_BAND",
uniqueConstraints=
@UniqueConstraint(columnNames={"active_band_user", "active_band_date"})
)
Problem
I am using SEAM 2/Hibernate along with PostgreSQL 9 database. I have the following table ``` Active Band =========== active_band_id serial active_band_user text active_band_date timestamp active_band_process integer ``` I would like to add a constraint that ensures each new entry has a unique combination of active_band_user and active_band_date. There could potentially be many attempted inserts per second so I need this to be as efficient as possible, is there a SEAM / hibernate annotation I can use in the entity mapping? Thanks in advance