From: Richard Huxton <dev@archonet.com>
To: ries@jongert.nl
To: pgsql-sql@postgresql.org
Subject: Re: Dublicates pairs in a table.
Date: Mon, 16 Sep 2002 16:08:27 +0100
Message-ID: <200209161608.27501.dev@archonet.com> (raw)
In-Reply-To: <000201c25d90$87230c10$6500000a@IT000>
References: <000201c25d90$87230c10$6500000a@IT000>
On Monday 16 Sep 2002 3:51 pm, Ries van Twisk wrote:
> Dear guys/girls,
>
> I have a small question which I could not clearly find in the postgreSQL
> manual.
>
> if I create this table and index
> CRAEATE TABLE test (
> id SERIAL,
> c1 VARCHAR(32),
> c2 VARCHAR(32),
> c3 VARCHAR(32)
> );
>
> CREATE UNIQUE INDEX test_idx ON test(id, c1,c2);
Close, try
CREATE UNIQUE INDEX test_idx ON test (c1,c2)
> what I try to archive here is that I don't want duplicate pais in my table:
> example
>
> INSET INTO test (c1,c2) VALUES('a', 'a'); -- Not allowed since we already
> have a duplicate ('a', 'a') pair
> What I want to know is that if this is smart do do, or is there a other
> better way to make sure I don't insert duplicate pairs in my database.
> I'm not sure if a stored procedure is better in my case since I don't
> really need the index on columns c1 or c2.
Unless test is a very small table with lots of inserts/deletions I'd just use
the index, otherwise you'll have to scan the table and check for another copy
anyway.
HTH
- Richard Huxton
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To: pgsql-sql@postgresql.org
Cc: dev@archonet.com, ries@jongert.nl
Subject: Re: Dublicates pairs in a table.
In-Reply-To: <200209161608.27501.dev@archonet.com>
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