//25

select luong

from nhanvien

where luong>=all

//26

select distinct manv,ten,tenpb,luong luonglonnhat

from nhanvien nv,phongban pb

where nv.mapb=pb.mapb

and luong >= all(select luong from nhanvien)

//28+29

select distinct nv.manv,ten,sum(thoigian) tongthoigian

from nhanvien nv,phancong p

where nv.manv=p.manv

group by nv.manv,ten

having sum(thoigian) >= all(select sum(thoigian)

from phancong

group by manv)

//30

select distinct nv.manv,ten,sum(thoigian) tongthoigian

from nhanvien nv,phancong p

where nv.manv=p.manv

group by nv.manv,ten

having sum(thoigian) <= all(select sum(thoigian)

from phancong

group by manv)

//31

select distinct nv.manv,ten,sum(thoigian) tongthoigian

from nhanvien nv,phancong p

where nv.manv=p.manv

group by nv.manv,ten

having sum(thoigian) >= 150 

//33

giong cau 31

//37

select distinct pb.mapb,tenpb,luong luonglonnhat

from nhanvien nv,phongban pb

where nv.mapb=pb.mapb and

luong >= all(select luong from nhanvien)

//39

select distinct pb.mapb,tenpb,holot,ten,luong luonglonnhat

from nhanvien nv,phongban pb

where nv.mapb=pb.mapb

and luong >= all

(select luong from nhanvien n1 where n1.mapb=nv.mapb)

SELECT TS.MATR, TENTR, COUNT(SOBD) AS SOLUONGCC

FROM Truong as TR, ThiSinh as TS

WHERE TR.MATR=TS.MATR and CCNGHE = 1

GROUP BY TS.MATR, TENTR

ORDER BY TENTR

SELECT GV.MATR, TENTR, COUNT(MAGV) AS SOLUONGGV

FROM Truong as TR, GiaoVien as GV

WHERE TR.MATR=GV.MATR

GROUP BY GV.MATR, TENTR

ORDER BY TENTR

SELECT SOPT, COUNT(SOBD) AS SOLUONGTS

FROM ThiSinh

GROUP BY SOPT

HAVING COUNT(SOBD)>25