Re: Small SQL Puzzle

Paul Watson wrote: > > Consider the following > > select col1, count(*) > from tab1 > group by 1 > having count(*) = 1 > union > select col1, count(*) > from tab2 > group by 1 > having count(*) = 1> > Gives x rows > > Next > > select col1 > from tab1 > union > select col1 > from tab2 > into temp table;> > select col1, count(*) > from temp > having count(*) =1> > gives y rows > > The obvious question is why doesn't x=y? > The obvious answer is to check the SQL itself and make sure that the ALL you think is in the statement is actually there when you read it. Whoops! -- Paul Watson # WF Software Ltd # It said run using Windows 95 Tel: +44 1436 674629 # or better in the manual Fax: +44 1436 678693 # so I used Unix www.wfsoftware.co.uk #