A.SELECT sno FROMSCWHERE sname=“数据库”ANDgrade=MAX(grade)
B.SELECT sno FROMSCFOR sname=“数据库”ORgrade>MAX(grade)
C.SELECT sno FROMSCWHERE shame=“数据库”ANDgrade=(SELECTMAX(grade)FROMsc)
D.SELECT son FROMSCFOR sname=“数据库”ORgrade=(SELECTMAX(grade.FROMsc)