Message-ID: <46FB880B.70003@prosyst.com>
Date: Thu, 27 Sep 2007 12:38:03 +0200
From: Venelin Arnaudov <v.arnaudov@prosyst.com>
User-Agent: Thunderbird 2.0.0.6 (Windows/20070728)
MIME-Version: 1.0
To: Richard Huxton <dev@archonet.com>
CC: pgsql-sql@postgresql.org
Subject: Re: Problems with bulk update
References: <46FB6822.9060507@prosyst.com> <46FB776D.5080406@archonet.com>
In-Reply-To: <46FB776D.5080406@archonet.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

I have tried this
gforge=> UPDATE data_table
gforge->    SET field2_new=(SELECT new_id FROM mapping_table WHERE
old_id= data_table.field2_old);

and

gforge-> update data_table set field2_new_=mt.new_id FROM data_table dt,
mapping_table mt WHERE dt.field2_old=mt.old_id;

but initially I got error. "ERROR:  column data_table.old_brand_id does
not exist"


It took me an eternity to realize that it is because of a missing entry
in the mapping table. I have added the record and the update run correctly.

Thank you very much

Kindest regards,
Venelin Arnaudov


Richard Huxton wrote:
> Venelin Arnaudov wrote:
>> Hi
>>
>> I want to update the values of one column of a table based on the
>> matches in a second table
>
>> something like
>> update table1
>>  set table1.field2_new=table2.new_id
>>  from table2
>>  where table1.field2_old=table2.old_id;
>
> Did you try it?
>
> http://www.postgresql.org/docs/8.2/static/sql-update.html
>
> PG has a non-standard "FROM" extension for just this purpose.
>