Re: Generate char surrogate key

From: Richard Huxton <dev(at)archonet(dot)com>
To: Josué Maldonado <josue(at)lamundial(dot)hn>, pgsql-general(at)postgresql(dot)org
Subject: Re: Generate char surrogate key
Date: 2004-03-19 19:48:01
Message-ID: 200403191948.01298.dev@archonet.com
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On Friday 19 March 2004 19:25, Josué Maldonado wrote:
> Hello list,
>
> Have a table with char(3) column, the column should contain values like
> '001','002','003'... and so on, keys must be correlatives no
> '001','005','007' should be allowed, any idea how to get it done using a
> trigger?

You can lock the table, then do something like:
SELECT key_column FROM table_name ORDER BY key_column DESC LIMIT 1;
Add one to the value you get and that's the next in order.

Of course that won't help you if there are deletions/renumberings etc.

--
Richard Huxton
Archonet Ltd

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