Обсуждение: update column

Dear list,

sorry, I already posted this, but it did not seem to have been accepted by
the mailing list. So here's my second try:

I need to update all rows of a column ('parent') based on a subquery that
returns me the first four digits of another column ('id'):

UPDATE admin SET parent=(SELECT SUBSTR(id,1,4) FROM admin);


After executing, I get the following error-message:

"more than one row returned by a subquery used as an expressionmore than one
row returned by a subquery used as an expression"


I am not quite sure about that, but maybe I need to construct a
function/loop to fulfill this task?

thanks for help.

Stefan 

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UPDATE admin
SET parent = SUBSTR(id,1,4);

Doesn't it do what you want?

Best,
Oliveiros

----- Original Message ----- 
From: "ssylla" <stefansylla@gmx.de>
To: <pgsql-sql@postgresql.org>
Sent: Thursday, February 09, 2012 1:58 AM
Subject: [SQL] update column


> Dear list,
>
> sorry, I already posted this, but it did not seem to have been accepted by
> the mailing list. So here's my second try:
>
> I need to update all rows of a column ('parent') based on a subquery that
> returns me the first four digits of another column ('id'):
>
> UPDATE admin SET parent=(SELECT SUBSTR(id,1,4) FROM admin);
>
>
> After executing, I get the following error-message:
>
> "more than one row returned by a subquery used as an expressionmore than 
> one
> row returned by a subquery used as an expression"
>
>
> I am not quite sure about that, but maybe I need to construct a
> function/loop to fulfill this task?
>
> thanks for help.
>
> Stefan
>
> --
> View this message in context: 
> http://postgresql.1045698.n5.nabble.com/update-column-tp5468330p5468330.html
> Sent from the PostgreSQL - sql mailing list archive at Nabble.com.
>
> -- 
> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
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