Question re: serial

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Question re: serial

От:
Michael Satterwhite <michael@weblore.com>
Дата:
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I have a table with a primary key defined as serial unique. When I insert a 
row into the table, I need to get the value of that row back so that I can 
use it to link rows in another table to it. How do I do that in Postgresql? I 
know that I can define a sequence and insert the value manually, but is there 
a way to query the value of the most recently inserted serial column of a 
row?

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Re: Question re: serial

От:
Bruno Wolff III <bruno@wolff.to>
Дата:
On Sat, Apr 24, 2004 at 12:24:03 -0500, Michael Satterwhite  wrote:
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> 
> I have a table with a primary key defined as serial unique. When I insert a 
> row into the table, I need to get the value of that row back so that I can 
> use it to link rows in another table to it. How do I do that in Postgresql? I 
> know that I can define a sequence and insert the value manually, but is there 
> a way to query the value of the most recently inserted serial column of a 
> row?

When you use a serial type there a sequence is created for you. You
can reference the most recent value of that sequence within the current
session using currval.

You can use the \d command in psql to see what sequence is being used to
calculate the default value.

Re: Question re: serial

От:
Devrim GUNDUZ <devrim@gunduz.org>
Дата:
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Hi,

On Sat, 24 Apr 2004, Michael Satterwhite wrote:

> I have a table with a primary key defined as serial unique. When I insert a
> row into the table, I need to get the value of that row back so that I can
> use it to link rows in another table to it. How do I do that in Postgresql? I
> know that I can define a sequence and insert the value manually, but is there
> a way to query the value of the most recently inserted serial column of a
> row?

See currval() and nextval() functions:

Regards,
- -- 
Devrim GUNDUZ	       
devrim@gunduz.org				devrim.gunduz@linux.org.tr 		http://www.TDMSoft.com		http://www.gunduz.org
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