11.正确答案：(
1.PRIMARY KEY
2.CHECK VALUES IN (\'F\',\'M\')或CHECK (stusek IN (\'F\',\'M\'))
3.REFERNCES School(schno)
)
12.正确答案：(
1.Club .clubname
2.COUNT(joinClub.stuno)) AS clubstunum
3.GROUP
4.UNION
5.JoinClub
)
13.正确答案：(
1.Student
2.row
3.SET schstunum=schunum+1 where School.schno=nrow.schno
4.SET schstunum=schunum-1 where School.schno=orow.schno
)
14.正确答案：(
1.ORDER
2.Student.schno或School.schno
)