实验报告二

• 实验目的
• • 实验内容和主要步骤：
  • • 实验中遇到的问题和心得体会

实验目的

1.掌握SQL查询语句的一般格式
2.掌握简单数据查询操作
3.熟练掌握各种查询条件的表示
4.掌握排序和分组操作在SQL语句中的实现
5.掌握集函数的使用

实验内容和主要步骤：

第2题：
1>

SELECT
	sname,
	sno,
	sdept
FROM
	a.student;

2>

3>

SELECT * FROM a.sc;
select distinct sno from a.sc

4>

SELECT
	sno
FROM
	a.sc
WHERE
	grade < 60
GROUP BY
	sno;

5>

SELECT
	sname, ssex
FROM
	 a.student
WHERE
	not sdept = 'CS'
OR sdept = 'IS';

6>

select sno,grade from a.sc where cno=004 order by grade desc;

7>

select cno,count(cno)
from a.cs
group by cno;

好像出问题了……

8>

select sname,sage,sdept
from
a.student
where
sdept='cs'

9>

select
sno,sname,sage,sdept
from
a.student
where sage between 18 and 20;

10>

select*from
a.student
where sname like'liu%'

11>

select distinct sno 
from a.sc 
where cno='1'and sno 
in(select distinct sno from a.sc where cno='2')

12>

SELECT Sname ,2003-Sage FROM  a.student;

13>

select sno,
cno from a.sc where grade=0;

14>

select sno from a.sc
group by sno having sum(grade)>200;

15>

select cno,
count(distinct sno)
from a.sc
where grade<60 group by cno;

16>

select sname,avg(grade)
from a.sc,a.student 
where a.student.sno=a.sc.sno and grade<60
group by sno
having by count(grade)>=3

报错了……

17>

select* from a.student where sage between 10 and 19;

18>

select* from a.student order by sdept asc,sage desc;

19>

select avg(grade) from a.sc where cno =001 group by cno;

20>

select max(grade)from a.sc where cno=003 group by cno;

21>

select sno,sum(grade)from a.sc group by sno;

实验中遇到的问题和心得体会

1.总是空格和缩进问题报错
2.表格没打全，运行没有得到想要的结果
3.因为打的表格不全所以有时候查询结果为空
4.以代码为主建表得合适