Dave Smith <dave.smith@xxxxxxxxxxx> writes: > I am trying to add a unique constraint on a column that can be null. The > documentation states that null is treated as non equal values but I want > them to be equal. Is there another way of doing this other than writing > a before insert trigger? UNIQUE constraints on NULLable columns work fine. It's not clear from the above what you're looking for. Are you really saying that you want 'NULL = NULL' to return 't'? -Doug ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly