第1关：子查询

1、SQL子查询使用的量词包括___BCD___。
A、EXISTS
B、ANY
C、SOME
D、ALL

2、经常与子查询一起使用的运算符有__ABCD____。
A、IN
B、EXISTS
C、ANY
D、ALL

3、使用EXISTS实现子查询时，必须使用内、外查询的相同意义的列进行比较运算。(B)
A、对
B、错

第2关：子查询-练习

use course;
 /****请在此编写代码，操作完毕之后点击评测******/
 
 /**********Begin**********/
select * from teacher where department_id="101";
  
 /**********End**********/

第3关：子查询-练习一

use course;
 /****请在此编写代码，操作完毕之后点击评测******/
 
  select distinct student_id,student_name 
  from student 
where student_id 
in(select distinct student_id from choose where score=82);

  select distinct student_id,student_name 
  from student 
  where student_id 
   in (select distinct student_id from choose group by student_id having avg(score)>70);
 /**********End**********/

第4关：子查询-练习二

use course;
 /****请在此编写代码，操作完毕之后点击评测******/
 
 /**********Begin**********/
  select distinct student.student_id,student.student_name 
  from student INNER join choose on student.student_id=choose.student_id
WHERE choose.score>=ALL 
(select score from choose where student_id='201710201102');

  select distinct department_id,department_name 
  from department 
  where department_id 
  not in (SELECT DISTINCT department_id FROM teacher);
   
 /**********End**********/

第5关：子查询-练习三

 use course;
 /****请在此编写代码，操作完毕之后点击评测******/
 
 /**********Begin**********/
  ( select s.student_id 学工号, student_name 姓名, gender 性别
from student s join choose c on s.student_id=c.student_id
group by s.student_id
order by sum(score) desc limit 3 )
union 
( select teacher_id, teacher_name, gender from teacher
	order by teacher_id desc limit 2
)
 /**********End**********/