Просто добавьте нужные столбцы в ORDER BY
:
ORDER BY t.GameId, t.GameSuplierId
Например:
DECLARE @table TABLE
(
ID INT,
GameId INT,
GameSuplierId INT NULL
)
INSERT INTO @table
(
ID,
GameId,
GameSuplierId
)
VALUES
(1, 1, NULL)
, (2, 2, NULL)
, (3, 3, 1)
, (4, 3, 2)
, (5, 3, 3)
SELECT
*
FROM @table t
ORDER BY t.GameId, t.GameSuplierId