嵌套查询

 1 create table chengji (
 2 name varchar(10),
 3 kecheng varchar(10),
 4 fenshu int
 5 );
 6 insert into chengji values(‘张三‘, ‘语文‘, 81);
 7 insert into chengji values(‘张三‘, ‘数学‘, 75);
 8 insert into chengji values(‘李四‘, ‘语文‘, 76);
 9 insert into chengji values(‘李四‘, ‘数学‘, 90);
10 insert into chengji values(‘王五‘, ‘语文‘, 81);
11 insert into chengji values(‘王五‘, ‘数学‘, 100);
12 insert into chengji values(‘王五‘, ‘英语‘, 90);
13 
14 
15 -- 用一条SQL语句查询出每门课都大于80分的学生姓名
16 select distinct name 
17 from chengji 
18 where name not in ( 
19 select distinct name 
20 from chengji 
21 where fenshu <= 80);