On Sun, Jul 15, 2007 at 07:07:26AM -0400, r937 wrote: > > But ... AVG() is acting on just the non-null rows. > > as per the spec, yes Yes. It's amazing what a few hours of real sleep will do. SUM( CASE WHEN test.score IS NULL THEN 1 ELSE 0 END ) AS is_incomplete -- Bill Moseley moseley at hank.org