对于教学数据库的三个基本表： 　　 　　学生 S(S#,SNAME,AGE,SEX) 　　 　　学习 SC(S#,C#,GRADE)

怎么出完题目就不见人了，也不来确认？？

1,select s,sname from S where age<22 and sex='女'

2,select count(*) from SC

3,select sname,age where sex='男' and age>(select max(age) from S where sex='女')

4,insert into S values('S9','WU',18)

5,delete from SC where grade is null

6,update SC set grade=grade*1.05 where c='C4' and grade<=75

update SC set grade=grade*1.04 where c='C4' and grade>75

7,select sname from S where sex='女' and sno in(

select sno from SC where c in(

select c from C where teacher='LIU老师'))

8,select c,cname from C where c in(

select c from SC SC1 where exists(

select * from SC SC2 where SC2.c=SC1.c and SC2.s in(

select S.s from S)))

9,select s,sname from S where sex='男' and age>23

10,select s from S where exists(

select * from SC where SC.s=S.s and c in(

select c from C where teacher='LIU老师'))

11,select SC1.s

from (select SC.s,count(*) countnum from SC group by SC.s) SC1

where SC1.countnum>=2

12,select c,avg(grade) from SC

where c in(select C.c from C where teacher='LIU老师')

group by SC.c

13,select sname,age from S where sname like 'WANG%'

14,insert into STUDENT

select S.s,S.sname,S.sex from S where not exists(

select * from SC where S.s=SC.s and grade<80)

15,select s,c from SC where grade is null

16,select S1.sname,S1.age from S S1 where S1.sex='男' and S1.age>(

select avg(age) from S S2 where S2.sex='女')

--1

SELECT C#,CNAME FROM C WHERE C# IN(

SELECT C# FROM SC GROUP BY C# HAVING COUNT(S#)=(SELECT MAX(S#) FROM S)

)

--2

update SC set SC.GRADE=SC.GRADE*1.05 from S where SC.GRADE<(select avg(SC.GRADE) from SC) and S.SEX='0'

--3

SELECT S#,SNAME FROM S WHERE S# IN(

select S# from SC group by S# having count(C#)>=3

)

--4

update SC set SC.GRADE=60 from C where C.CNAME='数学' and C.C#=SC.C#

--5

select C#,CNAME FROM C WHERE C# not IN(

select SC.C# from SC left join S on S.S#=SC.S# where S.SNAME='张三'

)

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