Re: Create loop in postgresql

this give an error.

select name,ges_kw_zgb, SELECT round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2);

ERROR:  syntax error at or near "SELECT"

LINE 2: select name,ges_kw_zgb, SELECT round(100 * (ges_kw_zgb / (se...

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Von: salah jubeh <s_jubeh@yahoo.com>
An: Robert Buckley <robertdbuckley@yahoo.com>; "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>
Gesendet: 17:45 Montag, 3.September 2012
Betreff: Re: [GENERAL] Create loop in postgresql

I am wondering why do not you write it like this

select name,ges_kw_zgb, select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2) ......

Regards

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From: Robert Buckley <robertdbuckley@yahoo.com>
To: "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>
Sent: Monday, September 3, 2012 5:30 PM
Subject: [GENERAL] Create loop in postgresql

Hi,

I am trying to loop through the records in a table and update a column. I can do this with a case statement but I would like to simplify this to a simple loop statement. I can´t seem to work out how to do it though.

Here is the case statement.

select name,ges_kw_zgb,

case

When name='Bad Harzburg' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))

When name='Braunlage' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))

When name='Braunschweig' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))

When name='Büddenstedt' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))

End as z

from energie.tennet_auswertung_2010

;

 Instead of having to write the name variable in the function, I would just like to iterate through each record and execute the select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2) command. 

If anyone can help I´d me grateful,

cheers,

Rob