câu lênh như này!
5a)
SELECT phieudathang.hoten, phanloaibanh.*
FROM phieudathang INNER JOIN
phanloaibanh ON phieudathang.maloaibanh = phanloaibanh.maloaibanh INNER JOIN
thanhphanphu ON phieudathang.matpphu = thanhphanphu.matpphu CROSS JOIN
nhanvien where hoten = 'CongTruong'
5b)
SELECT *
FROM phanloaibanh full outer join phieudathang on phanloaibanh.maloaibanh = phieudathang.maloaibanh
where maphieu IS NULL
5c)
Select * from phieudathang where ngaygiogiaohang= '2015-04-13 00:00:00.000' order by hoten desc
5d)
Select phanloaibanh.maloaibanh , phieudathang.maphieu , phieudathang.hoten, (thanhphanphu.giatpphu * phieudathang.soluongtpphu + phanloaibanh.gialoai * phieudathang.soluong) as gia from phieudathang left join phanloaibanh on phieudathang.maloaibanh=phanloaibanh.maloaibanh left join thanhphanphu on phieudathang.matpphu = thanhphanphu.matpphu