On Mon, 09 May 2005 12:57:41 -0400, Mark Fenbers wrote
> I want to update a column in myTable. The value this column is set
> todepends on a nested select statement which sometimes returns 0
> rowsinstead of 1. This is a problem since the column I'm trying to
> updateis set to refuse nulls. Here's a sample:
>
> update myTable set myColumn = (Select altColumn from altTable
> wherealtColumn != 'XXX' limit 1) where myColumn = 'XXX';
>
> MyColumn cannot accept nulls, but sometimes "Select altColumn
> ..."returns 0 rows, and thus, the query fails.
>
> Is there a way to set a default value to be inserted into myColumn
> ifand when "select altColumn ..." returns zero rows?
>
> Mark
Mark,
I do not know if it will work but I would try the COALESCE function.
http://www.postgresql.org/docs/8.0/interactive/functions-conditional.html
Kind Regards,
Keith