I'm not completely sure why the "char" parameter isn't working. The table field "LastName" is nvarchar(50). A "char" can be implicitly converted to an "nvarchar".

But converting your "char" parameter to an "nvarchar" first will solve your problem:

CREATE PROCEDURE FindEmployee @EmpLName char(20)

AS

DECLARE @LName nvarchar(20)

SET @LName = RTRIM(@EmpLName) + '%'

--SELECT @EmpLName = RTRIM(@EmpLName) + '%';

SELECT c.FirstName, c.LastName, a.City

FROM Person.Contact c JOIN Person.Address a ON c.ContactID = a.AddressID

WHERE c.LastName LIKE @LName --@EmpLName;

GO

EXEC FindEmployee @EmpLName = 'Barb';

GO