Re: not so sequential sequences

From: louis gonzales <gonzales(at)linuxlouis(dot)net>
To: Rhys Stewart <rhys(dot)stewart(at)gmail(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: not so sequential sequences
Date: 2006-10-18 03:49:59
Message-ID: 4535A467.8080103@linuxlouis.net
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Rhys,
You could create a sequence, then make the "seq" attribute to your table
have a default value of:
seq integer default nextval('your_sequence')

Then every time an insert is done into your table, the "seq" will
increment. You alternatively could make your "insert" statement have
for that position, the nextval('your_sequence')

Does that help?

Rhys Stewart wrote:

> Hi all, looking for a method to number a table sequentially, but the
> sequence only increments if the value in a certain column is
> different. as in
>
>
> seq | parish
> ------------------------
> 1 | Kingston
> 1 | Kingston
> 1 | Kingston
> 1 | Kingston
> 2 | Lucea
> 3 | Morant Bay
> 3 | Morant Bay
> 3 | Morant Bay
> 4 | Port Antonio
> 5 | Savannah-La-Mar
> 5 | Savannah-La-Mar
> 5 | Savannah-La-Mar
>
> so i guess i would order by a certain column and then the 'magic
> sequence' would be a column that only increments when the column
> changes.
>
> Rhys
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster

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