Re: insert without oids

От: Neil Conway
Тема: Re: insert without oids
Дата: ,
Msg-id: 1137187755.2509.6.camel@localhost.localdomain
(см: обсуждение, исходный текст)
Ответ на: insert without oids  (Michael Stone)
Ответы: Re: insert without oids  (Michael Stone)
Список: pgsql-performance

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insert without oids  (Michael Stone, )
 Re: insert without oids  (Michael Fuhr, )
 Re: insert without oids  (Neil Conway, )
  Re: insert without oids  (Michael Stone, )

On Fri, 2006-01-13 at 15:10 -0500, Michael Stone wrote:
> OIDs seem to be on their way out, and most of the time you can get a
> more helpful result by using a serial primary key anyway, but I wonder
> if there's any extension to INSERT to help identify what unique id a
> newly-inserted key will get? Using OIDs the insert would return the OID
> of the inserted row, which could be useful if you then want to refer to
> that row in a subsequent operation. You could get the same result by
> manually retrieving the next number in the sequence and using that value
> in the insert, but at the cost of additional DB operations.

There's really no additional operations required:

INSERT INTO t1 VALUES (...);
INSERT INTO t2 VALUES (currval('t1_id_seq'), ...);

You need a separate SELECT if you want to use the generated sequence
value outside the database, although the INSERT ... RETURNING extension
will avoid that (there's a patch implementing this, although it is not
yet in CVS).

-Neil




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