From: | Sascha Ziemann <ziemann(at)secunet(dot)de> |
---|---|
To: | pgsql-sql(at)postgresql(dot)org |
Subject: | UNIQUE constraint |
Date: | 2004-08-06 18:25:02 |
Message-ID: | m37jscdszl.fsf@sn-e0310.ek.secunet.de |
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Thread: | |
Lists: | pgsql-sql |
Hi,
I have a question about the UNIQUE constraint. The documentation
describes this example:
CREATE TABLE example (
a integer,
b integer,
c integer,
UNIQUE (a, c)
);
But it is not clean to me. Does the above example mean that the list
of pairs must be unique or is it only a short version for this
constraint:
CREATE TABLE example (
a integer UNIQUE,
b integer,
c integer UNIQUE
);
Does the following table fullfill the UNIQUE clause of the example
from the Postgres documentation?
a b c
-----
1 2 3
1 1 1
cu Sascha
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