[转] 比较久早前的叁个sql面试题及答案.

发布时间:2019-11-05  栏目:NoSQL  评论:0 Comments

SQL数据库面试题以至答案

Student(Sno,Sname,Sage,Ssex)
学子表       Sno:学号;Sname:学生姓名;Sage:学生年龄;Ssex:学子性别
Course(Cno,Cname,Tno)
课程表                    Cno,课程编号;Cname:课程名字;Tno:教师编号
SC(Sno,Cno,score)
战表表                             Sno:学号;Cno,课程编号;score:战表
Teacher(Tno,Tname) 助教表                        Tno:教师编号;
Tname:教授名字

 

创造数据表:

create table Student(

Sno varchar(10) not null primary key,

Sname varchar(20) null,

Sage int null,

Ssex varchar(2) null

)

create table Course(

Cno varchar(10) not null primary key,

Cname varchar(20) null,

Tno varchar(20) null

)

create table SC(

Sno varchar(10) not null primary key,

Cno varchar(10) not null primary key,

score int null

)

create table Teacher(

Tno varchar(20) primary key not null,

Tname varchar(20) null

)

问题:
1、查询“001”课程比“002”课程成绩高的享有学员的学号;
  select a.Sno from (select Sno,score from SC where Cno=’001′) a,(select
Sno,score
  from SC where Cno=’002′) b
  where a.score>b.score and a.Sno=b.Sno;
2、查询平均战绩超乎60分的同学的学号和平均战绩;
    select Sno,avg(score)
    from sc
    group by Sno having avg(score) >60;
3、查询全体同学的学号、姓名、选课数、总成绩;
  select Student.Sno,Student.Sname,count(SC.Cno),sum(score)
  from Student left Outer join SC on Student.Sno=SC.Sno
  group by Student.Sno,Sname
4、查询姓“李”的民间兴办教授的个数;
  select count(distinct(Tname))
  from Teacher
  where Tname like ‘李%’;
5、查询没学过“叶平”老师课的校友的学号、姓名;
    select Student.Sno,Student.Sname
    from Student 
    where Sno not in (select distinct( SC.Sno) from SC,Course,Teacher
where SC.Cno=Course.Cno and Teacher.Tno=Course.Tno  and
Teacher.Tname=’叶平’);
6、查询学过“001”何况也学过数码“002”课程的同窗的学号、姓名;
  select Student.Sno,Student.Sname from Student,SC where
Student.Sno=SC.Sno and SC.Cno=’001’and exists( Select * from SC as
SC_2 where SC_2.Sno=SC.Sno and SC_2.Cno=’002′);
7、查询学过“叶平”老师所教的全数课的同桌的学号、姓名;
  select Sno,Sname
  from Student
  where Sno in (select Sno from SC ,Course ,Teacher where
SC.Cno=Course.Cno and Teacher.Tno=Course.Tno and Teacher.Tname=’叶平’
group by Sno having count(SC.Cno)=(select count(Cno) from
Course,Teacher  where Teacher.Tno=Course.Tno and Tname=’叶平’));
8、查询课程编号“002”的战表比课程编号“001”课程低的持有同学的学号、姓名;
  Select Sno,Sname from (select Student.Sno,Student.Sname,score ,(select
score from SC SC_2 where SC_2.Sno=Student.Sno and SC_2.Cno=’002′)
score2
  from Student,SC where Student.Sno=SC.Sno and Cno=’001′) S_2 where
score2 <score;
9、查询全体科目成绩小于60分的同室的学号、姓名;
  select Sno,Sname
  from Student
  where Sno not in (select Student.Sno from Student,SC where
S.Sno=SC.Sno and score>60);
10、查询未有学全全数课的同班的学号、姓名;
    select Student.Sno,Student.Sname
    from Student,SC
    where Student.Sno=SC.Sno group by  Student.Sno,Student.Sname having
count(Cno) <(select count(Cno) from Course);

11、查询至少有一门课与学号为“1001”的同室所学相仿的同学的学号和人名;
    select Sno,Sname from Student,SC where Student.Sno=SC.Sno and Cno in
select Cno from SC where Sno=’1001′;
12、查询最少学过学号为“001”同学所有一门课的别的同学学号和人名;
    select distinct SC.Sno,Sname
    from Student,SC
    where Student.Sno=SC.Sno and Cno in (select Cno from SC where
Sno=’001′);
13、把“SC”表中“叶平”老师教的课的实绩都改进为此课程的平分成绩;
    update SC set score=(select avg(SC_2.score)
    from SC SC_2
    where SC_2.Cno=SC.Cno ) from Course,Teacher where Course.Cno=SC.Cno
and Course.Tno=Teacher.Tno and Teacher.Tname=’叶平’);
14、查询和“1002”号的同校学习的学科完全相仿的别的同学学号和姓名;
    select Sno from SC where Cno in (select Cno from SC where
Sno=’1002′)
    group by Sno having count(*)=(select count(*) from SC where
Sno=’1002′);
15、删除学习“叶平”老师课的SC表记录;
    Delect SC
    from course ,Teacher 
    where Course.Cno=SC.Cno and Course.Tno= Teacher.Tno and
Tname=’叶平’;
16、向SC表中插入一些记录,那几个记录必要相符以下标准:未有上过编号“003”课程的同窗学号、2、
    号课的平均成绩;
    Insert SC select Sno,’002′,(Select avg(score)
    from SC where Cno=’002′) from Student where Sno not in (Select Sno
from SC where Cno=’002′);
17、按平均成绩从高到低呈现全体学子的“数据库”、“集团管理”、“克罗地亚语”三门的教程成绩,按如下情势显得:
学子ID,,数据库,公司处理,匈牙利(Magyarország卡塔尔语,有效课程数,有效平均分
    SELECT Sno as 学生ID
        ,(SELECT score FROM SC WHERE SC.Sno=t.Sno AND Cno=’004′) AS
数据库
        ,(SELECT score FROM SC WHERE SC.Sno=t.Sno AND Cno=’001′) AS
公司管理
        ,(SELECT score FROM SC WHERE SC.Sno=t.Sno AND Cno=’006′) AS
英语
        ,COUNT(*) AS 有效课程数, AVG(t.score) AS 平均成绩
    FROM SC AS t
    GROUP BY Sno
    ORDER BY avg(t.score) 
18、查询各科成绩最高和最低的分:以如下情势显得:课程ID,最高分,最低分
    SELECT L.Cno As 课程ID,L.score AS 最高分,R.score AS 最低分
    FROM SC L ,SC AS R
    WHERE L.Cno = R.Cno and
        L.score = (SELECT MAX(IL.score)
                      FROM SC AS IL,Student AS IM
                      WHERE L.Cno = IL.Cno and IM.Sno=IL.Sno
                      GROUP BY IL.Cno)
        AND
        R.Score = (SELECT MIN(IR.score)
                      FROM SC AS IR
                      WHERE R.Cno = IR.Cno
                  GROUP BY IR.Cno
                    );
19、按各科平均战绩从低到高和及格率的比例从高到低依次
    SELECT t.Cno AS 课程号,max(course.Cname)AS
课程名,isnull(AVG(score),0) AS 平均战绩
        ,100 * SUM(CASE WHEN  isnull(score,0)>=60 THEN 1 ELSE 0
END)/COUNT(*) AS 及格百分数
    FROM SC T,Course
    where t.Cno=course.Cno
    GROUP BY t.Cno
    ORDER BY 100 * SUM(CASE WHEN  isnull(score,0)>=60 THEN 1 ELSE 0
END)/COUNT(*) DESC
20、查询如下课程平均成绩和及格率的比例(用”1行”展现):
集团管理(001卡塔 尔(阿拉伯语:قطر‎,马克思(002卡塔 尔(英语:State of Qatar),OO&UML (003卡塔尔国,数据库(004卡塔 尔(英语:State of Qatar)
    SELECT SUM(CASE WHEN Cno =’001′ THEN score ELSE 0 END)/SUM(CASE Cno
WHEN ‘001’ THEN 1 ELSE 0 END) AS 集团管理平均分
        ,100 * SUM(CASE WHEN Cno = ‘001’ AND score >= 60 THEN 1 ELSE
0 END)/SUM(CASE WHEN Cno = ‘001’ THEN 1 ELSE 0 END) AS
公司处理及格百分数
        ,SUM(CASE WHEN Cno = ‘002’ THEN score ELSE 0 END)/SUM(CASE Cno
WHEN ‘002’ THEN 1 ELSE 0 END) AS 马克思平均分
        ,100 * SUM(CASE WHEN Cno = ‘002’ AND score >= 60 THEN 1 ELSE
0 END)/SUM(CASE WHEN Cno = ‘002’ THEN 1 ELSE 0 END) AS
马克思及格百分数
        ,SUM(CASE WHEN Cno = ‘003’ THEN score ELSE 0 END)/SUM(CASE Cno
WHEN ‘003’ THEN 1 ELSE 0 END) AS UML平均分
        ,100 * SUM(CASE WHEN Cno = ‘003’ AND score >= 60 THEN 1 ELSE
0 END)/SUM(CASE WHEN Cno = ‘003’ THEN 1 ELSE 0 END) AS UML及格百分数
        ,SUM(CASE WHEN Cno = ‘004’ THEN score ELSE 0 END)/SUM(CASE Cno
WHEN ‘004’ THEN 1 ELSE 0 END) AS 数据库平均分
        ,100 * SUM(CASE WHEN Cno = ‘004’ AND score >= 60 THEN 1 ELSE
0 END)/SUM(CASE WHEN Cno = ‘004’ THEN 1 ELSE 0 END) AS
数据库及格百分数
  FROM SC
21、查询分歧老师所教差别学科平均分从高到低展现
  SELECT max(Z.Tno) AS 教授ID,MAX(Z.Tname) AS 教授姓名,C.Cno AS
课程ID,MAX(C.Cname) AS 课程名称,AVG(Score) AS 平均成绩
    FROM SC AS T,Course AS C ,Teacher AS Z
    where T.Cno=C.Cno and C.Tno=Z.Tno
  GROUP BY C.Cno
  ORDER BY AVG(Score) DESC
22、查询如下课程战绩第 3 名到第 6
名的学子成绩单:集团管理(001卡塔尔国,马克思(002卡塔尔国,UML
(003卡塔 尔(阿拉伯语:قطر‎,数据库(004卡塔尔国
    [学生ID],[学子姓名],公司管理,马克思,UML,数据库,平均成绩
    SELECT  DISTINCT top 3
      SC.Sno As 学子学号,
        Student.Sname AS 学子姓名 ,
      T1.score AS 企业管理,
      T2.score AS 马克思,
      T3.score AS UML,
      T4.score AS 数据库,
      ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) +
ISNULL(T4.score,0) as 总分
      FROM Student,SC  LEFT JOIN SC AS T1
                      ON SC.Sno = T1.Sno AND T1.Cno = ‘001’
            LEFT JOIN SC AS T2
                      ON SC.Sno = T2.Sno AND T2.Cno = ‘002’
            LEFT JOIN SC AS T3
                      ON SC.Sno = T3.Sno AND T3.Cno = ‘003’
            LEFT JOIN SC AS T4
                      ON SC.Sno = T4.Sno AND T4.Cno = ‘004’
      WHERE student.Sno=SC.Sno and
      ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) +
ISNULL(T4.score,0)
      NOT IN
      (SELECT
            DISTINCT
            TOP 15 WITH TIES
            ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0)

  • ISNULL(T4.score,0)
          FROM sc
                LEFT JOIN sc AS T1
                          ON sc.Sno = T1.Sno AND T1.Cno = ‘k1’
                LEFT JOIN sc AS T2
                          ON sc.Sno = T2.Sno AND T2.Cno = ‘k2’
                LEFT JOIN sc AS T3
                          ON sc.Sno = T3.Sno AND T3.Cno = ‘k3’
                LEFT JOIN sc AS T4
                          ON sc.Sno = T4.Sno AND T4.Cno = ‘k4’
          ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) +
    ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC);

23、总计列印各科战表,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[
<60]
    SELECT SC.Cno as 课程ID, Cname as 课程名称
        ,SUM(CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS
[100 – 85]
        ,SUM(CASE WHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS
[85 – 70]
        ,SUM(CASE WHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS
[70 – 60]
        ,SUM(CASE WHEN score < 60 THEN 1 ELSE 0 END) AS [60 -]
    FROM SC,Course
    where SC.Cno=Course.Cno
    GROUP BY SC.Cno,Cname;

24、查询学毕生均战表及其排名
      SELECT 1+(SELECT COUNT( distinct 平均战表)
              FROM (SELECT Sno,AVG(score) AS 平均战表
                      FROM SC
                  GROUP BY Sno
                  ) AS T1
            WHERE 平均战绩 > T2.平均战表) as 排名,
      Sno as 学子学号,平均战表
    FROM (SELECT Sno,AVG(score) 平均成绩
            FROM SC
        GROUP BY Sno
        ) AS T2
    O宝马X3DE奥德赛 BY 平均成绩 desc;
 
25、查询各科战表前三名的记录:(不构思成绩并列情形)
      SELECT t1.Sno as 学生ID,t1.Cno as 课程ID,Score as 分数
      FROM SC t1
      WHERE score IN (SELECT TOP 3 score
              FROM SC
              WHERE t1.Cno= Cno
            ORDER BY score DESC
              )
      ORDER BY t1.Cno;
26、查询每门科目被选修的学子数
  select Cno,count(Sno) from sc group by Cno;
27、查询出只选修了一门科目标整个上学的小孩子的学号和姓名
  select SC.Sno,Student.Sname,count(Cno) AS 选课数
  from SC ,Student
  where SC.Sno=Student.Sno group by SC.Sno ,Student.Sname having
count(Cno)=1;
28、查询男人、女子人数
    Select count(Ssex) as 匹内人数 from Student group by Ssex having
Ssex=’男’;
    Select count(Ssex) as 女人人数 from Student group by Ssex having
Ssex=’女’;
29、查询姓“张”的学子名单
    SELECT Sname FROM Student WHERE Sname like ‘张%’;
30、查询同名同种性别学子名单,并总结同名家数
  select Sname,count(*) from Student group by Sname
having  count(*)>1;;
31、壹玖捌肆年出生的学子名单(注:Student表中Sage列的门类是datetime)
    select Sname,  CONVERT(char (11),DATEPART(year,Sage)) as age
    from student
    where  CONVERT(char(11),DATEPART(year,Sage))=’1981′;
32、查询每门课程的平均战表,结果按平均成绩升序排列,平均成绩同样时,按学科号降序排列
    Select Cno,Avg(score) from SC group by Cno order by Avg(score),Cno
DESC ;
33、查询平均成绩超乎85的兼具学员的学号、姓名和平均战表
    select Sname,SC.Sno ,avg(score)
    from Student,SC
    where Student.Sno=SC.Sno group by SC.Sno,Sname
having    avg(score)>85;
34、查询课程名称叫“数据库”,且分数低于60的学习者姓名和分数
    Select Sname,isnull(score,0)
    from Student,SC,Course
    where SC.Sno=Student.Sno and SC.Cno=Course.Cno
and  Course.Cname=’数据库’and score <60;
35、查询全体学生的选课景况;
    SELECT SC.Sno,SC.Cno,Sname,Cname
    FROM SC,Student,Course
    where SC.Sno=Student.Sno and SC.Cno=Course.Cno ;
36、查询任何一门学科战表在70分以上的真名、课程名称和分数;
    SELECT  distinct student.Sno,student.Sname,SC.Cno,SC.score
    FROM student,Sc
    WHERE SC.score>=70 AND SC.Sno=student.Sno;
37、查询比不上格的科目,并按学科号从大到小排列
    select Cno from sc where scor e <60 order by Cno ;
38、查询课程编号为003且课程战表在80分以上的上学的小孩子的学号和人名;
    select SC.Sno,Student.Sname from SC,Student where SC.Sno=Student.Sno
and Score>80 and Cno=’003′;
39、求选了学科的上学的儿童人数
    select count(*) from sc;
40、查询选修“叶平”老师所授课程的学员中,成绩最高的上学的小孩子姓名及其成绩
    select Student.Sname,score
    from Student,SC,Course C,Teacher
    where Student.Sno=SC.Sno and SC.Cno=C.Cno and C.Tno=Teacher.Tno and
Teacher.Tname=’叶平’ and SC.score=(select max(score)from SC where
Cno=C.Cno );
41、查询各种科目及相应的选修人数
    select count(*) from sc group by Cno;
42、查询不相同学科成绩相通的学员的学号、课程号、学子战绩
  select distinct  A.Sno,B.score from SC A  ,SC B where A.Score=B.Score
and A.Cno <>B.Cno ;
43、查询每门功成绩最棒的前两名
    SELECT t1.Sno as 学生ID,t1.Cno as 课程ID,Score as 分数
      FROM SC t1
      WHERE score IN (SELECT TOP 2 score
              FROM SC
              WHERE t1.Cno= Cno
            ORDER BY score DESC
              )
      ORDER BY t1.Cno;
44、计算每门课程的学员选修人数(超越10人的课程才计算卡塔尔。必要输出课程号和选修人数,查询结果按人口降序排列,查询结果按人头降序排列,若人数相像,按学科号升序排列 
    select  Cno as 课程号,count(*) as 人数
    from  sc 
    group  by  Cno
    order  by  count(*) desc,Cno 
45、检索起码选修两门学科的学子学号
    select  Sno 
    from  sc 
    group  by  Sno
    having  count(*)  >  =  2
46、查询任何学子都选修的学科的课程号和科目名
    select  Cno,Cname 
    from  Course 
    where  Cno  in  (select  Cno  from  sc group  by  Cno) 
47、查询没学过“叶平”老师授课的任一门科指标学子姓名
    select Sname from Student where Sno not in (select Sno from
Course,Teacher,SC where Course.Tno=Teacher.Tno and SC.Cno=course.Cno and
Tname=’叶平’);
48、查询两门以上不如格课程的同桌的学号及其平均成绩
    select Sno,avg(isnull(score,0)) from SC where Sno in (select Sno
from SC where score <60 group by Sno having count(*)>2)group by
Sno;
49、检索“004”课程分数小于60,按分数降序排列的同班学号
    select Sno from SC where Cno=’004’and score <60 order by score
desc;

表className中犹如下分类:

classID   className
1              衣服
2              裤子
5              帽子
10            鞋子

表productInfo犹如下记录:

productID             productName            parentID           
clickNum

1                           
汉子服装                      1                         90           
–衣性格很顽强在艰难险阻或巨大压力面前不屈项目中那条记下的点击率最高
2                           
女士衣裳                      1                         80
3                           
男人裤子                      2                         70
4                           
女士裤子                      2                         90           
–裤子连串中那条记下点击率最高
5                           
男子帽子                      5                         15
6                           
女士帽子                      5                       
 30            –帽子种类中那条点击率最高
7                           
男生鞋子                      10                      
65            –鞋子种类中那条点击率最高
8                           
女士鞋子                      10                       52
9                           
女士鞋子1                    10                       54

现行反革命须求分别把衣性格很顽强在艰难险阻或巨大压力面前不屈,裤子,帽子,鞋子这一个品种中点击率最高的一条记下搜索来,然后再降序排列,结果应如下:

productID             productName            clickNum
1                            男人衣裳                      90
4                            女士裤子                      90
7                            男子鞋子                      65
6                            女士帽子                      30

以下为兑现进度:

/*
职能:
寻找体系表[className]中的每一个门类下点击率最高的那条记下,然后将这几个记录降序排列
作者: vivianhu
整理:
kgdiwss(笔者只是增加了批注以至重命名了部分变量)
日期: 2006-4-17
*/

/* 即使存在不常表tTable,则先将它删除 */
if exists (
select * from dbo.sysobjects
where id = object_id(N'[dbo].[tTable]’) and OBJECTPROPERTY(id,
N’IsUserTable’) = 1
)
drop table [dbo].[tTable]

GO

/* 创造有时表 */
create table tTable
(
productid int,
productname varchar(10),
clicknum int
)

/*  变量评释 */
declare @classID int 

/*  定义游标 */
declare cursor_classID   
CURSOR FOR
SELECT classID FROM className

/*
开拓游标
@@FETCH_STATUS
回来被 FETCH
语句实施的尾声游标的气象,实际不是任何当前被连接展开的游标的图景。
0 代表 FETCH 语句成功。
*/
OPEN cursor_classID
FETCH NEXT FROM cursor_classID INTO @classID
WHILE @@FETCH_STATUS = 0

/* 寻找某风度翩翩连串中式点心击率最高的一条记录 */
BEGIN

 insert into tTable
 select  top 1 productID,productName,clickNum from productInfo
  where parentID = @classID
   order by clickNum desc

   FETCH NEXT FROM cursor_classID
   INTO @classID

END

/* 关闭游标 */
CLOSE cursor_classID

/* 删除游标援引 */
DEALLOCATE cursor_classID

/* 对不时表中的记录依照点击率举办降序排列 */
select * from tTable order by clickNum desc

/* 删除偶尔表 */
drop table tTable

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