SET @RequestedDate = NULL;
SET @DeadlineDate = NULL;

SELECT DISTINCT(ps.RESULT),
p.ID,
p.CompletedDate,
p.Deadline,
p.Requested,
p.LastName, p.FirstName,
su.FullName,
tr.ResultDescription
FROM  projects p
INNER JOIN Projects_Services ps ON ps.ProjectID = p.ID
LEFT OUTER JOIN ossi_systemusers su ON su.IdentID = p.EnteredBy
LEFT OUTER JOIN Types_Results tr ON tr.ResultID = ps.RESULT
WHERE CompletedDate IS NOT NULL AND p.Requested >= IFNULL(@RequestedDate, p.Requested) AND p.Deadline >= IFNULL(@DeadlineDate, p.Deadline)
ORDER BY Deadline DESC