On Thu, 27 Apr 2006, Phillip Tornroth wrote:
I have a problem in a number of my tables. I'd like to add uniqueness
constraints across multiple columns, but some of the columns are nullable.
This gives me trouble since when I create a constraint on columns A and B..
I'd like the constraint to be enforced such that you couldn't insert values
("value for A", null) twice. I understand why the constraints work this way,
but I'm wondering if anyone knows of a workaround.
Phill,
You likely want a multicolumn unique index created like so:
CREATE UNIQUE INDEX foo_A_B_unique_idx ON foo (A,B);
See the docs here:
http://www.postgresql.org/docs/current/interactive/indexes-unique.html
--
Jeff Frost, Owner <[EMAIL PROTECTED]>
Frost Consulting, LLC http://www.frostconsultingllc.com/
Phone: 650-780-7908 FAX: 650-649-1954
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