[转]T-SQL_面试题

2015-05-19

1 创建表插入数据

Student(S#,Sname,Sage,Ssex) 学生表
Course(C#,Cname,T#) 课程表
SC(S#,C#,score) 成绩表
Teacher(T#,Tname) 教师表

1.1 Student

 Create table Student

 (

 S# number(4),

 Sname varchar2(9) not null,

 Ssex varchar2(3),

 Sage date,

 constraint Student_S#_Pk primary key(S#)

 );

 insert into Student values(1001,'李志国','男',to_date('26-9-1985','dd-mm-yyyy'));

 insert into Student values(1002,'李甜甜','女',to_date('6-2-1987','dd-mm-yyyy'));

 insert into Student values(1003,'张小燕','女',to_date('18-11-1984','dd-mm-yyyy'));

 insert into Student values(1004,'王菲','男',to_date('3-6-1985','dd-mm-yyyy'));

 insert into Student values(1005,'杜宇','女',to_date('25-4-1986','dd-mm-yyyy'));

 insert into Student values(1006,'彭大生','男',to_date('28-12-1988','dd-mm-yyyy'));

 insert into Student values(1007,'王亮','男',to_date('1-8-1983','dd-mm-yyyy'));

 insert into Student values(1008,'赵婷婷','女',to_date('2-2-1984','dd-mm-yyyy'));

1.2 Course

Create table Course

(

C# number(3),

Cname varchar2(12) not null,

T# number(4),

constraint Course_C#_Pk primary key(C#),

constraint Course_T#_Fk foreign key (T#) references Teacher(T#)

);

insert into Course values(001,'企业管理',2003);

insert into Course values(002,'马克思',2001);

insert into Course values(003,'OO'||'&'||'UML',2002);

insert into Course values(004,'数据库',2004);

insert into Course values(005,'英语',2005);

insert into Course values(006,'大学语文',2005);

insert into Course values(007,'现代企业',2003);

1.3 SC

Create table SC

(

S# number(4),

C# number(4),

score number(3),

constraint SC__S#_C#_Pk primary key(S#,C#),

constraint Sc_S#_Fk foreign key (S#) references Student(S#),

constraint Sc_C#_Fk foreign key (C#) references Course(C#)

);

insert into SC values(1001,1,87);

insert into SC values(1001,3,66);

insert into SC values(1001,2,77);

insert into SC values(1001,5,45);

insert into SC values(1001,7,67);

insert into SC values(1002,4,26);

insert into SC values(1002,1,86);

insert into SC values(1003,3,67);

insert into SC values(1003,2,97);

insert into SC values(1003,5,67);

insert into SC values(1004,5,78);

insert into SC values(1004,3,67);

insert into SC values(1004,4,49);

insert into SC values(1005,4,76);

insert into SC values(1005,2,84);

insert into SC values(1005,3,35);

insert into SC values(1006,3,54);

insert into SC values(1006,2,76);

insert into SC values(1006,1,56);

insert into SC values(1007,1,56);

insert into SC values(1007,7,88);

insert into SC values(1007,2,89);

insert into SC values(1007,3,57);

insert into SC values(1007,4,99);

insert into SC values(1007,5,85);

insert into SC values(1008,1,76);

insert into SC values(1008,2,44);

insert into SC values(1008,4,87);

insert into SC values(1008,5,33);

insert into SC values(1002,6,65);

insert into SC values(1002,7,90);

insert into SC values(1006,6,67);

1.4 Teacher

Create table Teacher

(

T# number(4),

Tname varchar2(9) not null,

constraint Teacher_T#_Pk primary key(T#)

);

insert into Teacher values(2001,'李华');

insert into Teacher values(2002,'王力宏');

insert into Teacher values(2003,'叶平');

insert into Teacher values(2004,'王倩倩');

insert into Teacher values(2005,'李莉莉');

mysql

DROP TABLE IF EXISTS `student`;

CREATE TABLE `student` (

  `SId` int(11) unsigned NOT NULL AUTO_INCREMENT,

  `Sname` varchar(255) NOT NULL,

  `Ssex` varchar(255) DEFAULT NULL,

  `Sage` date DEFAULT NULL COMMENT 'CURRENT_TIMESTAMP',

  PRIMARY KEY (`SId`)

) ENGINE=InnoDB AUTO_INCREMENT=1009 DEFAULT CHARSET=utf8;

-- ----------------------------

-- Records of student

-- ----------------------------

INSERT INTO `student` VALUES ('', '李志国', '男', '1985-09-26');

INSERT INTO `student` VALUES ('', '李甜甜', '女', '1987-02-06');

INSERT INTO `student` VALUES ('', '张小燕', '女', '1984-11-18');

INSERT INTO `student` VALUES ('', '王菲', '男', '1986-06-03');

INSERT INTO `student` VALUES ('', '杜宇', '女', '1986-04-25');

INSERT INTO `student` VALUES ('', '彭大生', '男', '1988-08-28');

INSERT INTO `student` VALUES ('', '王亮', '男', '1983-08-01');

INSERT INTO `student` VALUES ('', '赵婷婷', '女', '1984-02-02');

DROP TABLE IF EXISTS `course`;

CREATE TABLE `course` (

  `CId` int(11) unsigned NOT NULL AUTO_INCREMENT,

  `TId` int(11) DEFAULT NULL,

  `Cname` varchar(255) DEFAULT NULL,

  PRIMARY KEY (`CId`)

) ENGINE=InnoDB AUTO_INCREMENT=1008 DEFAULT CHARSET=utf8;

-- ----------------------------

-- Records of course

-- ----------------------------

INSERT INTO `course` VALUES ('', '', '企业管理');

INSERT INTO `course` VALUES ('', '', '马克思');

INSERT INTO `course` VALUES ('', '', 'OO&UML');

INSERT INTO `course` VALUES ('', '', '数据库');

INSERT INTO `course` VALUES ('', '', '英语');

INSERT INTO `course` VALUES ('', '', '大学语文');

INSERT INTO `course` VALUES ('', '', '现代企业');

DROP TABLE IF EXISTS `sc`;

CREATE TABLE `sc` (

  `SCId` int(10) unsigned NOT NULL AUTO_INCREMENT,

  `SId` int(11) DEFAULT NULL,

  `CId` int(11) DEFAULT NULL,

  `score` int(255) DEFAULT NULL,

  PRIMARY KEY (`SCId`)

) ENGINE=InnoDB AUTO_INCREMENT=33 DEFAULT CHARSET=utf8;

-- ----------------------------

-- Records of sc

-- ----------------------------

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

INSERT INTO `sc` VALUES ('', '', '', '');

DROP TABLE IF EXISTS `teacher`;

CREATE TABLE `teacher` (

  `TId` int(10) unsigned NOT NULL AUTO_INCREMENT,

  `TName` varchar(255) DEFAULT NULL,

  PRIMARY KEY (`TId`)

) ENGINE=InnoDB AUTO_INCREMENT=2006 DEFAULT CHARSET=utf8;

-- ----------------------------

-- Records of teacher

-- ----------------------------

INSERT INTO `teacher` VALUES ('', '李华');

INSERT INTO `teacher` VALUES ('', '王力宏');

INSERT INTO `teacher` VALUES ('', '叶平');

INSERT INTO `teacher` VALUES ('', '王倩倩');

INSERT INTO `teacher` VALUES ('', '李莉莉');

2 T-SQL试题

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#='') a,(select s#,score from SC where C#='') b

where a.score>b.score and a.s#=b.s#;

-- mysql

SELECT a.SId

from (select SId,score from sc where CId='') a,(select SId,score from sc where CId='') b

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

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;

-- mysql

select SID, AVG(score)

from SC

GROUP BY SID

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

select student.SId,student.Sname,count(SC.Cid),sum(SC.score)

from student,SC

where student.SId=SC.SId

group by student.SId

4、查询姓“李”的老师的个数；

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

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');

select SId,Sname from Student where SId not in

(SELECT DISTINCT SC.SId from SC,Course,Teacher where SC.CId=Course.CId and Course.TId=Teacher.TId 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#=''and exists( Select * from SC  SC_2 where SC_2.S#=SC.S# and SC_2.C#='');

解析： 使用 exists关键字，用来判断是否存在的，当exists（查询）中的查询结果存在时则返回真，否则返回假。

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'));

解析：跟第5题的要求正好相反，且难度提高了。所有课程通过groupby 后的having条件实现

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#='') score2 from Student,SC where Student.S#=SC.S# and C#='') S_2

where score2 <score;

解析：跟第1题基本一样的问题，只是实现方式不一样。第1题的实现方式更适合我。

9、查询所有课程成绩小于60分的同学的学号、姓名；

select S#,Sname

from Student

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

解析：反过来说：没有一门课程大于等于60

10、查询没有学全所有课的同学的学号、姓名；

select Student.S#,Student.Sname

from Student,SC

where Student.S#=SC.S# group by Student.S#,Student.Sname having count(C#) <(select count(C#) from Course);

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 S#,Sname

from Student,SC

where Student.S#=SC.S# and C# in (select C# from SC where S#='');

13、把“SC”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩；

update SC

set score=(select avg(SC_2.score) from SC SC_2 where SC_2.C#=SC.C#)

from Course,Teacher

where Course.C#=SC.C# and Course.T#=Teacher.T# and Teacher.Tname='叶平');

-- mysql

update SC ,(SELECT SC.CId,AVG(SC.score) avgScore from SC,Course,Teacher where SC.CId=Course.CId and Course.TId=Teacher.TId and Teacher.Tname='叶平' GROUP BY SC.CId) a

set SC.score=a.avgScore

where SC.CId=a.CId

14、查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名；

select S#

from SC

where C# in (select C# from SC where S#='')

group by S#

having count(*)=(select count(*) from SC where S#='');

15、删除学习“叶平”老师课的SC表记录；

Delete SC

from course ,Teacher

where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='叶平';

16、向SC表中插入一些记录，这些记录要求符合以下条件：没有上过编号“003”课程的同学学号、“002”号课的平均成绩；

Insert into SC (S#,C#,score)

values（select S#,'',(Select avg(score)  from SC where C#='') from Student where S# not in (Select S# from SC where C#='')）;

17、按平均成绩从高到低显示所有学生的“数据库”、“企业管理”、“英语”三门的课程成绩，按如下形式显示：学生ID,,数据库,企业管理,英语,有效课程数,有效平均分

SELECT S# as 学生ID

    ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='') AS 数据库

    ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='') AS 企业管理

    ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='') AS 英语

    ,COUNT(*) AS 有效课程数, AVG(t.score) AS 平均成绩

FROM SC AS t

GROUP BY S#

ORDER BY avg(t.score)

18、查询各科成绩最高和最低的分：以如下形式显示：课程ID，最高分，最低分
    SELECT L.C# As 课程ID,L.score AS 最高分,R.score AS 最低分
    FROM SC L ,SC AS R
    WHERE L.C# = R.C# and
        L.score = (SELECT MAX(IL.score)
                      FROM SC AS IL,Student AS IM
                      WHERE L.C# = IL.C# and IM.S#=IL.S#
                      GROUP BY IL.C#)
        AND
        R.Score = (SELECT MIN(IR.score)
                      FROM SC AS IR
                      WHERE R.C# = IR.C#
                  GROUP BY IR.C#
                    );

-- mysql

SELECT DISTINCT

CId '课程ID',

(select Max(score) from SC SC1 where SC1.CId=SC.CId group by CId) '最高分',

(select Min(score) from SC SC2 where SC2.CId=SC.CId group by CId) '最低分 '

from SC order by CId;

19、按各科平均成绩从低到高和及格率的百分数从高到低顺序

SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩 ,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.C#=course.C#

GROUP BY t.C#

ORDER BY 100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC

SELECT t.CId AS '课程号',max(course.Cname)AS '课程名',ifnull(AVG(score),0) AS '平均成绩' ,100 * SUM(CASE WHEN ifnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS '及格百分数'

FROM SC T,Course

where t.CId=course.CId

GROUP BY t.CId

ORDER BY 100 * SUM(CASE WHEN ifnull(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百分数(用"1行"显示): 企业管理（001），马克思（002），OO&UML （003），数据库（004）

SELECT SUM(CASE WHEN C# ='' THEN score ELSE 0 END)/SUM(CASE C# WHEN '' THEN 1 ELSE 0 END) AS 企业管理平均分

    ,100 * SUM(CASE WHEN C# = '' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '' THEN 1 ELSE 0 END) AS 企业管理及格百分数

    ,SUM(CASE WHEN C# = '' THEN score ELSE 0 END)/SUM(CASE C# WHEN '' THEN 1 ELSE 0 END) AS 马克思平均分

    ,100 * SUM(CASE WHEN C# = '' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '' THEN 1 ELSE 0 END) AS 马克思及格百分数

    ,SUM(CASE WHEN C# = '' THEN score ELSE 0 END)/SUM(CASE C# WHEN '' THEN 1 ELSE 0 END) AS UML平均分

    ,100 * SUM(CASE WHEN C# = '' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '' THEN 1 ELSE 0 END) AS UML及格百分数

    ,SUM(CASE WHEN C# = '' THEN score ELSE 0 END)/SUM(CASE C# WHEN '' THEN 1 ELSE 0 END) AS 数据库平均分

    ,100 * SUM(CASE WHEN C# = '' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '' THEN 1 ELSE 0 END) AS 数据库及格百分数

FROM SC

22、查询如下课程成绩第 3 名到第 6 名的学生成绩单：企业管理（001），马克思（002），UML （003），数据库（004）
[学生ID],[学生姓名],企业管理,马克思,UML,数据库,总分

SELECT DISTINCT top 3

    SC.S# As 学生学号,

    Student.Sname AS 学生姓名 ,

    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.S# = T1.S# AND T1.C# = ''

        LEFT JOIN SC AS T2 ON SC.S# = T2.S# AND T2.C# = ''

        LEFT JOIN SC AS T3 ON SC.S# = T3.S# AND T3.C# = ''

        LEFT JOIN SC AS T4 ON SC.S# = T4.S# AND T4.C# = ''

    WHERE student.S#=SC.S# 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.S# = T1.S# AND T1.C# = 'k1'

            LEFT JOIN sc AS T2

                      ON sc.S# = T2.S# AND T2.C# = 'k2'

            LEFT JOIN sc AS T3

                      ON sc.S# = T3.S# AND T3.C# = 'k3'

            LEFT JOIN sc AS T4

                      ON sc.S# = T4.S# AND T4.C# = 'k4'

        ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC);

23、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60]

SELECT SC.C# 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.C#=Course.C#

GROUP BY SC.C#,Cname;

24、查询学生平均成绩及其名次

SELECT 1+(SELECT COUNT(distinct 平均成绩) FROM (SELECT S#,AVG(score) AS 平均成绩 FROM SCGROUP BY S# ) AS T1 WHERE 平均成绩 > T2.平均成绩) as 名次, S# as 学生学号,平均成绩

FROM (SELECT S#,AVG(score) 平均成绩 FROM SC GROUP BY S# ) AS T2

ORDER BY 平均成绩 desc;

25、查询各科成绩前三名的记录:(不考虑成绩并列情况)

SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数

FROM SC t1

WHERE score IN (SELECT TOP 3 score FROM SC WHERE t1.C#= C# ORDER BY score DESC )

ORDER BY t1.C#;

31、1981年出生的学生名单(注：Student表中Sage列的类型是datetime)

select Sname, CONVERT(char (11),DATEPART(year,Sage)) as age

from student

where CONVERT(char(11),DATEPART(year,Sage))='';

42、查询不同课程成绩相同的学生的学号、课程号、学生成绩

select distinct A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# <>B.C# ;