Обсуждение: Get last serial (autoincrement) value

Hi,

Anyone knows how to obtain last inserted serial (autoincrement) id? I
am currently using "SELECT id FROM table_name ORDER BY id DESC", and
then retrieve first row and desired value.

May be there is more elegant way? I am using ADODB. ADODB has function
which in theory allows to obtain
last inserted serial (autoincrement) id, but for Postgres it return OID.

This is from ADODB manual:

Insert_ID( )
Returns the last autonumbering ID inserted. Returns false if function
not supported.
Only supported by databases that support auto-increment or object id's,
such as PostgreSQL, MySQL and MSSQL currently. PostgreSQL returns the
OID, which can change on a database reload.


Thanks in advance for any suggestion.


*********************************************
*   Best Regards   ---   Andrei Verovski
*
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select currval('table_id_column_seq');


----- Original Message -----
From: "Andrei Verovski (aka MacGuru)" <andreil1@mail.starlett.lv>
To: <pgsql-php@postgresql.org>
Sent: Monday, September 01, 2003 03:34
Subject: [PHP] Get last serial (autoincrement) value


> Hi,
>
> Anyone knows how to obtain last inserted serial (autoincrement) id? I
> am currently using "SELECT id FROM table_name ORDER BY id DESC", and
> then retrieve first row and desired value.
>
> May be there is more elegant way? I am using ADODB. ADODB has function
> which in theory allows to obtain
> last inserted serial (autoincrement) id, but for Postgres it return OID.
>
> This is from ADODB manual:
>
> Insert_ID( )
> Returns the last autonumbering ID inserted. Returns false if function
> not supported.
> Only supported by databases that support auto-increment or object id's,
> such as PostgreSQL, MySQL and MSSQL currently. PostgreSQL returns the
> OID, which can change on a database reload.
>
>
> Thanks in advance for any suggestion.
>
>
> *********************************************
> *   Best Regards   ---   Andrei Verovski
> *
> *   Personal Home Page
> *   http://snow.prohosting.com/guru4mac
> *   Mac, Linux, DTP, Development, IT WEB Site
> *********************************************
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
>       subscribe-nomail command to majordomo@postgresql.org so that your
>       message can get through to the mailing list cleanly

At 06:34 AM 9/1/03, aka MacGuru wrote:
>Anyone knows how to obtain last inserted serial (autoincrement) id? I am
>currently using "SELECT id FROM table_name ORDER BY id DESC", and then
>retrieve first row and desired value.


Faster then your version:
SELECT id FROM table_name ORDER BY id DESC   LIMIT 1

The 'elegant' solution:
SELECT currval('tablename_sequence_id');

On Mon, Sep 01, 2003 at 13:34:32 +0300,
  Andrei Verovski <andreil1@mail.starlett.lv> wrote:
>
> Anyone knows how to obtain last inserted serial (autoincrement) id? I
> am currently using "SELECT id FROM table_name ORDER BY id DESC", and
> then retrieve first row and desired value.

How you want to do this, depends on what you what to do with the number.

Normally if you just inserted a record that would create a new id and you
want to use that id to enter in another table, then you want to call
currval.