Обсуждение: coalesce a null to a char ?
How can I do this....
selcet coalesce((select ‘y’ from foo where name = f.name),’n’) from foo f where...
So the query returns a “y” or “n” depending on whether or not the subquery is null.
I get...
“ERROR: failed to find conversion function from unknown to text”
On 06/04/2009 22:55, Gauthier, Dave wrote: > How can I do this.... > > selcet coalesce((select 'y' from foo where name = f.name),'n') from foo f where... > > So the query returns a "y" or "n" depending on whether or not the subquery is null. Are you sure that the subquery is returning any rows? Try something like this instead (not tested): select case when exists(select 1 from foo where name = f.name) then 'y' else 'n' end from foo.... Ray. ------------------------------------------------------------------ Raymond O'Donnell, Director of Music, Galway Cathedral, Ireland rod@iol.ie Galway Cathedral Recitals: http://www.galwaycathedral.org/recitals ------------------------------------------------------------------