Re: Complex Update - Mailing list pgsql-sql

From Richard Huxton
Subject Re: Complex Update
Date
Msg-id 200401051110.30065.dev@archonet.com
Whole thread Raw
In response to Complex Update  (John Coryat <john@coryat.com>)
List pgsql-sql
On Saturday 03 January 2004 09:20, John Coryat wrote:
> Problem: I have a table that has a field I want to plug with a value
> from other tables.
[snip]
> I would expect it to look something like this:
>
> update orderheader set total = (select sum(amount) from orderdetail
> where orderdetail.orderno=orderheader.orderno) ;

Looks fine to me. In general, you can do something of the form:

UPDATE ta SET a2 = (SELECT expr(b2) FROM tb WHERE b1=a1);

NOTE - make sure you understand what happens when there is no b1=a1 and what 
that will mean to your particular setup.

--  Richard Huxton Archonet Ltd


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