@Unique doesn't have any effect in DataNucleus w/ NeoDatis
Using JDO / DataNucleus / NeoDatis datastore
I added @Unique to a field of a persistable object, however I am allowed to create multiple objects which violate the unique constraint. The docs for DataNucleus/NeoDatis suggest that Unique fields are supported.
@PersistenceCapable
public class User {
@Persistent
@Unique
private String username;
//...
}
If I add multiple objects to the DB with the same user开发者_如何学JAVAname there's no problem doing so.
Did you specify a name for your unique constraint ?
@Unique(name="USERNAME_IDX")
private String username;
It appears that the DataNucleus implementation for NeoDatis doesn't support unique attributes. In NeoDatis it requires that you add a unique index on the field (see link below for NeoDatis forums describing this).
http://sourceforge.net/projects/neodatis-odb/forums/forum/619814/topic/3409305
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