Обсуждение: SQL Help - Obtaining ID of record INSERTED
Greetings.
INSERT INTO
orderstemp (customerid,datecreated)
VALUES
('5443','8/16/2005 12:00PM')
The table orderstemp has a unique identifier field, orderid (of type
SERIAL).
How can I obtain the orderid of the record inserted in the INSERT INTO
statement in postgresql?
MSSQL does it like this:
INSERT INTO
orderstemp (customerid,datecreated)
VALUES
('5443','8/16/2005 12:00PM')
SELECT @@identity as orderid
but this doens't work in postgresql.
Any ideas? Thanks in advance.
Greetings, all! As described in http://www.postgresql.org/docs/8.0/interactive/datatype.html#DATATYPE-SERIAL, column "type" SERIAL is really an integer type with an implicit sequence associated by default with that column. In order to get the last generated value from the sequence, use the "currval" function, as described in http://www.postgresql.org/docs/8.0/interactive/functions-sequence.html. Hope this helps! On 8/16/05, josh@segrestfarms.com <josh@segrestfarms.com> wrote: > Greetings. > > INSERT INTO > orderstemp (customerid,datecreated) > VALUES > ('5443','8/16/2005 12:00PM') > > The table orderstemp has a unique identifier field, orderid (of type > SERIAL). > > How can I obtain the orderid of the record inserted in the INSERT INTO > statement in postgresql? > > MSSQL does it like this: > > INSERT INTO > orderstemp (customerid,datecreated) > VALUES > ('5443','8/16/2005 12:00PM') > SELECT @@identity as orderid > > but this doens't work in postgresql. > > Any ideas? Thanks in advance. > > ---------------------------(end of broadcast)--------------------------- > TIP 1: 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 >
Check out http://www.postgresql.org/docs/8.0/interactive/functions-sequence.html You'll want to use something like "SELECT currval('<name of sequence>')". The thing is, your orderid field in orderstemp has a sequence which it uses to grab the next value. The currval function called with the name of the sequence as the parameter will give you results as you are accustomed to. However, it is a separate query and must be treated as such. Note that you need to call it using the same database connection. And sequences are special - they always update and do not roll back with failed transactions. If you used default serial notation in your create table statement, your table is likely named "orderid_id_seq": SELECT currval('orderid_id_seq'::text); Jason -----Original Message----- From: pgsql-admin-owner@postgresql.org [mailto:pgsql-admin-owner@postgresql.org]On Behalf Of josh@segrestfarms.com Sent: Tuesday, August 16, 2005 4:09 PM To: pgsql-admin@postgresql.org Subject: [ADMIN] SQL Help - Obtaining ID of record INSERTED Greetings. INSERT INTO orderstemp (customerid,datecreated) VALUES ('5443','8/16/2005 12:00PM') The table orderstemp has a unique identifier field, orderid (of type SERIAL). How can I obtain the orderid of the record inserted in the INSERT INTO statement in postgresql? MSSQL does it like this: INSERT INTO orderstemp (customerid,datecreated) VALUES ('5443','8/16/2005 12:00PM') SELECT @@identity as orderid but this doens't work in postgresql. Any ideas? Thanks in advance. ---------------------------(end of broadcast)--------------------------- TIP 1: 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
josh@segrestfarms.com wrote:
> Greetings.
>
> INSERT INTO
> orderstemp (customerid,datecreated)
> VALUES
> ('5443','8/16/2005 12:00PM')
>
> The table orderstemp has a unique identifier field, orderid (of type
> SERIAL).
>
> How can I obtain the orderid of the record inserted in the INSERT INTO
> statement in postgresql?
>
> MSSQL does it like this:
>
> INSERT INTO
> orderstemp (customerid,datecreated)
> VALUES
> ('5443','8/16/2005 12:00PM')
> SELECT @@identity as orderid
If you are in the same session you can do:
select currval('sequencename_of_orderid');
>
> but this doens't work in postgresql.
>
> Any ideas? Thanks in advance.
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: 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
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You got the suggestion using currval already so here's one alternative.
SELECT NEXTVAL('"orderid_sequence_name"');
Assume this value is $val then do
INSERT INTO orderstemp(orderid,...) VALUES ($val, ...);
I'm not sure if this is generally used, but this works and sometimes this
way is convenient for batch processing.
>SELECT @@identity as orderid
My 0.02$.
Regards,
Ben Kim
Developer
College of Education
Texas A&M University
On Tue, Aug 16, 2005 at 17:09:04 -0400,
"josh@segrestfarms.com" <josh@segrestfarms.com> wrote:
> Greetings.
>
> INSERT INTO
> orderstemp (customerid,datecreated)
> VALUES
> ('5443','8/16/2005 12:00PM')
>
> The table orderstemp has a unique identifier field, orderid (of type
> SERIAL).
>
> How can I obtain the orderid of the record inserted in the INSERT INTO
> statement in postgresql?
>
> MSSQL does it like this:
>
> INSERT INTO
> orderstemp (customerid,datecreated)
> VALUES
> ('5443','8/16/2005 12:00PM')
> SELECT @@identity as orderid
>
> but this doens't work in postgresql.
>
> Any ideas? Thanks in advance.
You want to use currval. In 8.0 you would use:
SELECT currval(pg_get_serial_sequence('orderstemp', 'orderid'));
Thank you.
You stated that the SELECT currval('orderid_id_seq') statement is a
separate query and must be treated as such.
This gives me cause for concern. My intention is to obtain the orderid
of the order inserted at that moment, but if I am to use a separate
query it would seem there is a chance (albeit a small one) that another
order could come through before I am able to obtain the orderid.
Jason Minion wrote:
>Check out http://www.postgresql.org/docs/8.0/interactive/functions-sequence.html
>
>You'll want to use something like "SELECT currval('<name of sequence>')". The thing
>is, your orderid field in orderstemp has a sequence which it uses to grab the
>next value. The currval function called with the name of the sequence as the
>parameter will give you results as you are accustomed to. However, it is a
>separate query and must be treated as such. Note that you need to call it
>using the same database connection. And sequences are special - they always
>update and do not roll back with failed transactions.
>
>If you used default serial notation in your create table statement, your table is
>likely named "orderid_id_seq":
>
>SELECT currval('orderid_id_seq'::text);
>
>Jason
>
>-----Original Message-----
>From: pgsql-admin-owner@postgresql.org
>[mailto:pgsql-admin-owner@postgresql.org]On Behalf Of
>josh@segrestfarms.com
>Sent: Tuesday, August 16, 2005 4:09 PM
>To: pgsql-admin@postgresql.org
>Subject: [ADMIN] SQL Help - Obtaining ID of record INSERTED
>
>
>Greetings.
>
>INSERT INTO
> orderstemp (customerid,datecreated)
>VALUES
> ('5443','8/16/2005 12:00PM')
>
>The table orderstemp has a unique identifier field, orderid (of type
>SERIAL).
>
>How can I obtain the orderid of the record inserted in the INSERT INTO
>statement in postgresql?
>
>MSSQL does it like this:
>
>INSERT INTO
> orderstemp (customerid,datecreated)
>VALUES
> ('5443','8/16/2005 12:00PM')
>SELECT @@identity as orderid
>
>but this doens't work in postgresql.
>
>Any ideas? Thanks in advance.
>
>---------------------------(end of broadcast)---------------------------
>TIP 1: 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
>
>
>
>
On Wed, Aug 17, 2005 at 08:39:22AM -0400, josh@segrestfarms.com wrote:
> You stated that the SELECT currval('orderid_id_seq') statement is a
> separate query and must be treated as such.
>
> This gives me cause for concern. My intention is to obtain the orderid
> of the order inserted at that moment, but if I am to use a separate
> query it would seem there is a chance (albeit a small one) that another
> order could come through before I am able to obtain the orderid.
No, there isn't; or rather, it doesn't matter. See the documentation
and the FAQ.
http://www.postgresql.org/docs/8.0/interactive/functions-sequence.html
Return the value most recently obtained by nextval for this
sequence in the current session. (An error is reported if nextval
has never been called for this sequence in this session.) Notice
that because this is returning a session-local value, it gives a
predictable answer whether or not other sessions have executed
nextval since the current session did.
http://www.postgresql.org/docs/faqs.FAQ.html#4.11.3
4.11.3) Doesn't currval() lead to a race condition with other users?
No. currval() returns the current value assigned by your session,
not by all sessions.
--
Michael Fuhr
josh@segrestfarms.com wrote:
> Thank you.
>
> You stated that the SELECT currval('orderid_id_seq') statement is a
> separate query and must be treated as such.
>
> This gives me cause for concern. My intention is to obtain the
> orderid of the order inserted at that moment, but if I am to use a
> separate query it would seem there is a chance (albeit a small one)
> that another order could come through before I am able to obtain the
> orderid.
sequences are transaction/session safe thus it is not a problem. It
would be a problem if *you* in your session inserted another record
or if you disconnected before you ran the currval but as long as you are
in the same session you are fine.
Sincerely,
Joshua D. Drake
>
> Jason Minion wrote:
>
>> Check out
>> http://www.postgresql.org/docs/8.0/interactive/functions-sequence.html
>>
>> You'll want to use something like "SELECT currval('<name of
>> sequence>')". The thing
>> is, your orderid field in orderstemp has a sequence which it uses to
>> grab the
>> next value. The currval function called with the name of the sequence
>> as the
>> parameter will give you results as you are accustomed to. However, it
>> is a
>> separate query and must be treated as such. Note that you need to
>> call it
>> using the same database connection. And sequences are special - they
>> always
>> update and do not roll back with failed transactions.
>>
>> If you used default serial notation in your create table statement,
>> your table is
>> likely named "orderid_id_seq":
>>
>> SELECT currval('orderid_id_seq'::text);
>>
>> Jason
>>
>> -----Original Message-----
>> From: pgsql-admin-owner@postgresql.org
>> [mailto:pgsql-admin-owner@postgresql.org]On Behalf Of
>> josh@segrestfarms.com
>> Sent: Tuesday, August 16, 2005 4:09 PM
>> To: pgsql-admin@postgresql.org
>> Subject: [ADMIN] SQL Help - Obtaining ID of record INSERTED
>>
>>
>> Greetings.
>>
>> INSERT INTO
>> orderstemp (customerid,datecreated)
>> VALUES
>> ('5443','8/16/2005 12:00PM')
>>
>> The table orderstemp has a unique identifier field, orderid (of type
>> SERIAL).
>>
>> How can I obtain the orderid of the record inserted in the INSERT
>> INTO statement in postgresql?
>>
>> MSSQL does it like this:
>>
>> INSERT INTO
>> orderstemp (customerid,datecreated)
>> VALUES
>> ('5443','8/16/2005 12:00PM')
>> SELECT @@identity as orderid
>>
>> but this doens't work in postgresql.
>>
>> Any ideas? Thanks in advance.
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 1: 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
>>
>>
>>
>>
>
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