Re: Unique cosntraint based on contents of a field?

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От Jaime Casanova
Тема Re: Unique cosntraint based on contents of a field?
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Msg-id r2g3073cc9b1004072048r159cf35hfe03576b8da8a627@mail.gmail.com
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Ответ на Unique cosntraint based on contents of a field?  (Warren Bell <warrenbell2@gmail.com>)
Ответы Re: Unique cosntraint based on contents of a field?  (Bruce Momjian <bruce@momjian.us>)
Список pgsql-general
On Wed, Apr 7, 2010 at 10:30 PM, Warren Bell <warrenbell2@gmail.com> wrote:
> Is there a way to create a unique constraint based on the content of a
> field? For instance, say you have an integer field where you only want one
> record with the number 1 in that field but there can be many records with
> say the number 2 or any other single number in that field.
>

create unique index unique_field_idx
on table1(field)
where field = 1;

--
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157

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