SQL数据库面试题以及答案
2015-09-09 14:33
495 查看
Student(S#,Sname,Sage,Ssex) 学生表 S#:学号;Sname:学生姓名;Sage:学生年龄;Ssex:学生性别
Course(C#,Cname,T#) 课程表 C#,课程编号;Cname:课程名字;T#:教师编号
SC(S#,C#,score) 成绩表 S#:学号;C#,课程编号;score:成绩
Teacher(T#,Tname) 教师表 T#:教师编号; Tname:教师名字
问题:
1、查询“001”课程比“002”课程成绩高的所有学生的学号;
select a.S# from (select s#,score from SC where C#=’001’) a,(select s#,score
from SC where C#=’002’) b
where a.score>b.score and a.s#=b.s#;
2、查询平均成绩大于60分的同学的学号和平均成绩;
select S#,avg(score)
from sc
group by S# 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#,Student.Sname,count(SC.C#),sum(score)
from Student left Outer join SC on Student.S#=SC.S#
group by Student.S#,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#,Student.Sname
from Student
where S# not in (select distinct( SC.S#) from SC,Course,Teacher where SC.C#=Course.C# 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;
select Student.S#,Student.Sname from Student,SC where Student.S#=SC.S# and SC.C#=’001’and exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#=’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#,Sname
from Student
where S# in (select S# from SC ,Course ,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname=’叶平’ group by S# having count(SC.C#)=(select count(C#) 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#,Sname from (select Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#=’002’) score2
from Student,SC where Student.S#=SC.S# and C#=’001’) S_2 where score2
Course(C#,Cname,T#) 课程表 C#,课程编号;Cname:课程名字;T#:教师编号
SC(S#,C#,score) 成绩表 S#:学号;C#,课程编号;score:成绩
Teacher(T#,Tname) 教师表 T#:教师编号; Tname:教师名字
问题:
1、查询“001”课程比“002”课程成绩高的所有学生的学号;
select a.S# from (select s#,score from SC where C#=’001’) a,(select s#,score
from SC where C#=’002’) b
where a.score>b.score and a.s#=b.s#;
2、查询平均成绩大于60分的同学的学号和平均成绩;
select S#,avg(score)
from sc
group by S# 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#,Student.Sname,count(SC.C#),sum(score)
from Student left Outer join SC on Student.S#=SC.S#
group by Student.S#,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#,Student.Sname
from Student
where S# not in (select distinct( SC.S#) from SC,Course,Teacher where SC.C#=Course.C# 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;
select Student.S#,Student.Sname from Student,SC where Student.S#=SC.S# and SC.C#=’001’and exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#=’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#,Sname
from Student
where S# in (select S# from SC ,Course ,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname=’叶平’ group by S# having count(SC.C#)=(select count(C#) 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#,Sname from (select Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#=’002’) score2
from Student,SC where Student.S#=SC.S# and C#=’001’) S_2 where score2
相关文章推荐
- 面试题41和为S的两个数字VS和为s的连续正数序列
- 面试题 23
- 像程序员一样思考 记录
- 黑马程序员———Objctive-C———【NSDictionary、NSMutableDictionary、NSFileManager】
- 黑马程序员———Objctive-C———【NSArray不可变数组、NSMutableArray可变数组】
- 黑马程序员———Objctive-C———【NSString及NSMutalbeString的使用】
- 【剑指offer】面试题7:用两个栈实现队列
- 【剑指offer】面试题6:重建二叉树
- 【剑指offer】面试题5:从尾到头打印链表
- 黑马程序员——线程间的通讯
- iOS面试专题
- 安卓面试宝典
- 面试题初级-求字符串最后一个单词的长度和判断ip地址的合法性
- 2015-9-8号两次前端面试(大众点评+七牛)
- Java面试题
- 黑马程序员-- 集合框架 (Collection, Iterator,泛型)
- 剑指Offer:面试题4 替换空格
- 给“夜猫子”程序员的科学熬夜指南
- 黑马程序员--抽象类和接口
- 程序员技术练级攻略