Originally posted by 11520104
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Hiển tham khảo:
Code:
select distinct ngaydi from lichbay lich1 where not exists (select maloai from loaimb loai1 where hangsx='boeing' and maloai not in (select lich2.maloai from loaimb loai2, lichbay lich2 where lich2.maloai = loai2.maloai and lich1.ngaydi = lich2.ngaydi) );
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