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 ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
