Hrishi Joshi <hjoshi@xxxxxxxxxxx> writes: > I need to define a Unique index on 3 non-PK fields (composite key) on my > table in PostgreSQL 8.0.3. > The problem is, if any of those 3 fields is Null, PostgreSQL allows > duplicate rows to be inserted. That is the behavior defined by the SQL standard. > But I need to know how can I make PostgreSQL throw error on attempt to > insert second record having same 3 field values, one of them being Null. You can't. Rethink your data representation, instead. You are misusing NULL if you think that it represents something unique. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
