Hi
Can anyone tell me how to create a UDF in SQL Server 2000 that returns a TABLE where the definition contains an IF statement?

I wanted to do something like:

create function fn_foo(@cli int) returns table as

return

if exists(select id from customers where cli=@cli)
select id from customers where cli=@cli

else
select 999 as id



or something a bit more complex.

If this doesn't work, is it possible to put a CASE construct in a WHERE clause in a SQL SELECT statement?

TIA,
Simon