年整理数据库嵌套查询实验报告

年整理数据库嵌套查询实验报告

年整理数据库嵌套查询实验报告 篇1

实验三：数据库的嵌套查询实验

实验目的 ：

加深对嵌套查询语句的理解。

实验内容：

使用 IN、比较符、ANY 或 ALL 和 EXISTS 操作符进行嵌套查询操作。

实验步骤：

一.使用带 N IN 谓词的子查询

1.查询与’刘晨’在同一个系学习的学生的信息: 比较 select * from student where sdept in

(select sdept from student where sname=“刘晨”)与: select * from student where sdept =

(select sdept from student where sname=“刘晨”)的异同

比较: select * from student where sdept =

(select sdept from student where sname=“刘晨”)and sname <> ‘刘晨’ 与: select S1.* from student S1, student S2 where S1.sdept=S2.sdept and S2.sname=“刘晨”的异同

2.查询选修了课程名为’信息系统’ 的学生的学号和姓名: 比较 select sno, sname from student where sno in(select sno from sc where cno in

(select cno from course where cname=“信息系统”))与: select sno, sname from student where sno in

(select sno from sc, course where sc.cno=course.cno and cname=“信息系统”)

3.查询选修了课程’1’和课程’2’的学生的学号: select sno from student where sno in(select sno from sc where cno=“1”)and sno in(select sno from sc where cno=“2”)

比较: 查询选修了课程’1’或课程’2’的学生的 sno: select sno from sc where cno=“1” or cno=“2”

比较连接查询:

select A.sno from sc A, sc B where A.sno=B.sno and A.cno=“1” and B.cno=“2”

二.使用带比较运算的子查询 4.查询比’刘晨’年龄小的所有学生的信息: select * from student where sage<

(select sage from student where sname=“刘晨”)

三.使用带 Any, All 谓词的子查询 5.查询其他系中比信息系(IS)某一学生年龄小的学生姓名和年龄;select sname, sage from student where sage

(select sage from student where sdept=“IS”)and sdept<>“IS”

6.查询其他系中比信息系(IS)学生年龄都小的学生姓名和年龄: select sname, sage from student where sage “IS”

7.查询与计算机系(CS)系所有学生的年龄均不同的学生学号, 姓名和年龄: select sno,sname,sage from student where sage<>all(select sage from student where sdept=“CS”)

四.使用带 s Exists 谓词的子查询和相关子查询

8.查询与其他所有学生年龄均不同的学生学号, 姓名和年龄: select sno,sname,sage from student A where not exists(select * from student B where A.sage=B.sage and A.sno<>B.sno)

9.查询所有选修了 1 号课程的学生姓名: select sname from student where exists(select * from sc where sno=student.sno and cno=“1”)

10.查询没有选修了 1 号课程的学生姓名: select sname from student where not exists(select * from sc where sno=student.sno and cno=“1”)

11.查询选修了全部课程的学生姓名: SQL Server 中:

select sname from student where not exists(select * from course where not exists(select * from sc where sno=student.sno and cno=course.cno))

11.查询至少选修了学生 95002 选修的全部课程的学生的学号: SQL Server 中: select distinct sno from sc A where not exists

(select * from sc B where sno=“95002”and not exists(select * from sc C where sno=A.sno and cno=B.cno))

12.求没有人选修的课程号 cno 和 cnamecname: select cno,cname from course C where not exists(select * from sc where sc.cno=C.cno)

13*.查询满足条件的(sno,cno)对, 其中该学号的学生没有选修该课程号 cno的课程 SQL Server 中: select sno,cno from student,course where not exists(select * from sc where cno=course.cno and sno=student.sno)

14*.查询每个学生的课程成绩最高的成绩信息(sno,cno,grade): select * from sc A where grade=(select max(grade)from sc where sno=A.sno)

思考: 如何查询所有学生都选修了的课程的课程号 cno? select cno

from sc

group by cno

having count(*)=(select count(*)from student)