Rick Debay Wrote:>

>> if D.SuplCde is 'ABC' and ISupplierCode is NULL, result will be

TRUE??

>Wrong. Since one has a value and the other is NULL, they are DISTINCT.
>The NOT would flip that to false.

OK, so Sasha is right, DISTINCT is unfortunately not going to work.
Any other suggestions for ((D.SuplCde = :ISupplierCode) or
(:ISupplierCode is null))
to be able to use indices?