CREATE PROCEDURE AddJobService (@JobNumber INT = NULL, @ServiceCode VARCHAR (15) = NULL, @Notes VARCHAR (200) = NULL, Hours INT = NULL)
AS
IF @JobNumber IS NULL OR @ServiceCode IS NULL OR @Notes IS NULL OR @Hours IS NULL
    BEGIN
    RaisError ('You must provide all information',16,1)
    END
IF NOT EXISTS (SELECT * FROM Job WHERE JobNumber = @JobNumber)
    BEGIN
    RaisError ('That job does not exist', 16,1)
    END
IF EXISTS (SELECT * FROM Job WHERE JobNumber = @JobNumber)
    BEGIN
    INSERT INTO JobService (JobNumber, ServiceCode, Notes, Hours)
    VALUES (@JobNumber, @ServiceCode, @Notes, @Hours)
    END
RETURN