CF,
> select
> (case when column1 = column2 then column3 end) as alias1,
> (case when column1 = column2 then column4 end) as alias2,
> (case when column1 = column2 then column5 end) as alias3,
> (case when column6 = column7 then column8 end) as alias4
> from
> mytable
Given the information you've given us (including your first e-mail), I can't
think of a better way to get the output you want than the above. You could
work through subselects, etc, but I think that would be even less efficient.
One thing you might want to think about is your whole approach to designing
this application; it may be that you can simplify your queries by changing
your table design.
--
Josh Berkus
Aglio Database Solutions
San Francisco