SQL笔试题：下面是学生表(student)的结构说明字段名称字段解释字段类型字段长度约束

s_id学号字符10PK

s_name学生姓名字符50Not null

s_age学生年龄数值3Not null

s-sex学生性别字符(男：1女：0)1Not null

下面是教师表(Teacher )的结构说明字段名称字段解释字段类型字段长度约束

t_id教师编号字符10PK

t_name教师名字字符50Not null

下面是课程表(Course)的结构说明字段名称字段解释字段类型字段长度约束

c_id课程编号字符10PK

c_name课程名字字符50Not null

t_id教师编号字符10Not null

下面是成绩表(SC)的结构说明字段名称字段解释字段类型字段长度约束

s_id学号字符10PK

c_id课程编号字符10Not null

score成绩数值3Not null

1、查询“001”课程比“002”课程成绩高的所有学生的学号；

select a.s_id from (select s_id,score from SC where C_ID='001') a,(select s_id,score

from SC where C_ID='002') b

where a.score>b.score and a.s_id=b.s_id;

2、查询平均成绩大于60分的同学的学号和平均成绩；

select S_ID,avg(score)

from sc

group by S_ID having avg(score) >60;

3、查询所有同学的学号、姓名、选课数、总成绩；

select Student.S_ID,Student.Sname,count(SC.C_ID),sum(score)

from Student left Outer join SC on Student.S_ID=SC.S_ID

group by Student.S_ID,Sname

4、查询姓“李”的老师的个数；

select count(distinct(Tname))

from Teacher

where Tname like '李%';

5、查询没学过“叶平”老师课的同学的学号、姓名；

select Student.S_ID,Student.Sname

from Student

where S_ID not in (select distinct( SC.S_ID) from SC,Course,Teacher where SC.C_ID=Course.C_ID and Teacher.T#=Course.T# and Teacher.Tname='叶平');

6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名；

elect Student.S_ID,Student.Sname from Student,SC where Student.S_ID=SC.S_ID and SC.C_ID='001'and exists( Select * from SC as SC_2 where SC_2.S_ID=SC.S_ID and SC_2.C_ID='002');

7、查询学过“叶平”老师所教的所有课的同学的学号、姓名；

select S_ID,Sname

from Student

where S_ID in (select S_ID from SC ,Course ,Teacher where SC.C_ID=Course.C_ID and Teacher.T#=Course.T# and Teacher.Tname='叶平' group by S_ID having count(SC.C_ID)=(select count(C_ID) from Course,Teacher where Teacher.T#=Course.T# and Tname='叶平'));

8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名；

Select S_ID,Sname from (select Student.S_ID,Student.Sname,score ,(select score from SC SC_2 where SC_2.S_ID=Student.S_ID and SC_2.C_ID='002') score2

from Student,SC where Student.S_ID=SC.S_ID and C_ID='001') S_2 where score2 < score;

9、查询所有课程成绩小于60分的同学的学号、姓名；

select S_ID,Sname

from Student

where S_ID not in (select S.S_ID from Student AS S,SC where S.S_ID=SC.S_ID and score>60);

10、查询没有学全所有课的同学的学号、姓名；

select Student.S_ID,Student.Sname

from Student,SC

where Student.S_ID=SC.S_ID group by Student.S_ID,Student.Sname having count(C_ID)

11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名；

select distinct S_ID,Sname from Student,SC where Student.S_ID=SC.S_ID and SC.C_ID in (select C_ID from SC where S_ID='1001');

12、查询至少学过学号为“001”同学所有一门课的其他同学学号和姓名；

select distinct SC.S_ID,Sname

from Student,SC

where Student.S_ID=SC.S_ID and C_ID in (select C_ID from SC where S_ID='001');