WHERE IS NULL, IS NOT NULL or NO WHERE clause depending on SQL Server parameter value

Question

I have a stored procedure in SQL Server 2000 that performs a search based on parameter values. For one of the parameters passed in, I need a different WHERE cla

Answer 1

This is how it can be done using CASE:

DECLARE @myParam INT;
SET @myParam = 1;

SELECT * 
  FROM MyTable
 WHERE 'T' = CASE @myParam
             WHEN 1 THEN 
                CASE WHEN MyColumn IS NULL THEN 'T' END
             WHEN 2 THEN
                CASE WHEN MyColumn IS NOT NULL THEN 'T' END
             WHEN 3 THEN 'T' END;