Stored Procedure Returns Different Data When You Run It In T-SQL

I have a stored procedure




Code Block
CREATE PROCEDURE WEA_SelectEmployeeListByCourseOrProject
@ProjectID int,
@CourseID int,
@blnIsSearch int,
@strUserName nvarchar(20)

AS
SET CONCAT_NULL_YIELDS_NULL OFF

DECLARE @strRole nvarchar(15),
@ContactID int
SELECT @strRole = Role, @ContactID = ContactID FROM Contact WHERE UserName = @strUserName
Select DISTINCT Contact.ContactID ID, UPPER(Surname + 'gd ' + Forename ) AS Description, UPPER(Surname + ' ' + Forename + ' ' + ContactReference) AS Description_CR
, UPPER(ISNULL(ContactReference,'')) ContactReference
FROM Contact
LEFT JOIN AssignedEmployee on Contact.ContactID = AssignedEmployee.ContactID
WHERE RUEmployee=1
AND
( ((@CourseID = 0 AND @blnIsSearch=1 ) OR COALESCE(AssignedEmployee.CourseID,0) = @CourseID))
AND
(@ProjectID = 0 OR COALESCE(AssignedEmployee.ProjectID,0) = @ProjectID)
AND
(
(@strRole = 'MIS_TUTOR' AND
(AssignedEmployee.ContactID = @ContactID
OR CourseID IN (SELECT CourseID FROM AssignedEmployee WHERE ContactID = @ContactID AND Lead = 1)
OR AssignedEmployee.ProjectID IN (SELECT ProjectID FROM AssignedEmployee WHERE CourseID IS NULL AND Lead = 1 AND ContactID = @ContactID))
)
OR
(@strRole <> 'MIS_TUTOR')
)
SET CONCAT_NULL_YIELDS_NULL ON
GO






now if i run this stored procedure in Query Analyzer like so...

exec wea_SelectEmployeeListByCourseOrProject 0,0,1,'K_T'

i get 48 records returned.

but if i lift the SQL out of the stored procedure and run it in Query Analyzer like so....





Code Block
SET CONCAT_NULL_YIELDS_NULL OFF

DECLARE @ProjectID int,
@CourseID int,
@blnIsSearch int,
@strUserName nvarchar(20)
SET @ProjectID = 0
SET @CourseID = 0
SET @blnIsSearch = 1
SET @strUserName = 'K_T'


DECLARE @Role nvarchar(15),
@ContactID int
SELECT @Role = Role, @ContactID = ContactID FROM Contact WHERE UserName = @strUserName
PRINT @ContactID
Select DISTINCT Contact.ContactID ID, UPPER(Surname + ' ' + Forename ) AS Description, UPPER(Surname + ' ' + Forename + ' ' + ContactReference) AS Description_CR
, UPPER(ISNULL(ContactReference,'')) ContactReference
FROM Contact
LEFT JOIN AssignedEmployee on Contact.ContactID = AssignedEmployee.ContactID
WHERE RUEmployee=1
AND
( ((@CourseID = 0 AND @blnIsSearch=1 ) OR COALESCE(AssignedEmployee.CourseID,0) = @CourseID)) -- the above line was modified to make sure only employees explicitly assigned to a project are brought back. unless it's a search
AND
(@ProjectID = 0 OR COALESCE(AssignedEmployee.ProjectID,0) = @ProjectID)
AND
(
(@Role = 'MIS_TUTOR'
AND ( (AssignedEmployee.ContactID = @ContactID OR CourseID IN (SELECT CourseID FROM AssignedEmployee WHERE ContactID = @ContactID AND Lead = 1)))
OR
AssignedEmployee.ProjectID IN (SELECT ProjectID FROM AssignedEmployee WHERE CourseID IS NULL AND Lead = 1 AND ContactID = @ContactID)
)
OR
(@Role <> 'MIS_TUTOR')
)


SET CONCAT_NULL_YIELDS_NULL ON







i only get 5 records returned???

so why do i get a difference when its the same SQL??

Username 'K_T' is of role 'MIS_TUTOR' therefore @Role = 'MIS_TUTOR'

any help on unravelling this mystery is appreciated!

Cheers,
Craig