Câu 74 dùng phép chia ngắn hơn nha mọi người.
SELECT * FROM dbo.DMSV AS SV3
WHERE SV3.MaSV != 'A03' AND NOT EXISTS
(
(
SELECT DISTINCT(KQ1.MaMH) FROM dbo.KetQua AS KQ1
WHERE KQ1.MaSV = 'A03'
)
EXCEPT
(
SELECT DISTINCT(Kq.MaMH) FROM dbo.DMSV AS SV JOIN dbo.KetQua AS KQ
ON KQ.MaSV = SV.MaSV
WHERE...