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844天前drop table sc; |
drop table student; |
drop table course; |
--学生表 |
create table student( |
id number(4) primary key, |
name varchar2(10) |
); |
--课程 |
create table course( |
id number(4) primary key, |
name1 varchar2(20) |
); |
--课程表 |
create table sc( |
sid number(4) references student(id), |
cid number(4) references course(id), |
grade number(4,2) |
); |
insert into student |
select 1,'小何' from dual union |
select 2,'小凳' from dual union |
select 3,'小宝' from dual union |
select 4,'小飞' from dual; |
insert into course values(1,'java'); |
insert into course values(2,'c#'); |
insert into course values(3,'sql'); |
insert into course values(4,'php'); |
insert into sc |
select 1,1,98 from dual union |
select 2,1,95 from dual union |
select 4,1,88 from dual union |
select 1,2,78 from dual union |
select 3,2,99 from dual union |
select 4,2,89 from dual union |
select 1,3,76 from dual union |
select 4,3,84 from dual union |
select 1,4,91 from dual union |
select 2,4,73 from dual; |
--查询选修所有课程的学生 |
select name from student where id in(select sid from sc group by |
sid having count(*)=(select count(*) from course)); |
--查询选修两门课程以上的学生 |
select name from student where id in(select sid from sc group by sid having count(*)>=2); |
by: 发表于：2017-09-28 14:48:15 顶(0) | 踩(0) 回复
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