[转]T-SQL_面试题
[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
1 Create table Student 2 ( 3 S# number(4), 4 Sname varchar2(9) not null, 5 Ssex varchar2(3), 6 Sage date, 7 constraint Student_S#_Pk primary key(S#) 8 ); 9 10 insert into Student values(1001,'李志国','男',to_date('26-9-1985','dd-mm-yyyy')); 11 insert into Student values(1002,'李甜甜','女',to_date('6-2-1987','dd-mm-yyyy')); 12 insert into Student values(1003,'张小燕','女',to_date('18-11-1984','dd-mm-yyyy')); 13 insert into Student values(1004,'王菲','男',to_date('3-6-1985','dd-mm-yyyy')); 14 insert into Student values(1005,'杜宇','女',to_date('25-4-1986','dd-mm-yyyy')); 15 insert into Student values(1006,'彭大生','男',to_date('28-12-1988','dd-mm-yyyy')); 16 insert into Student values(1007,'王亮','男',to_date('1-8-1983','dd-mm-yyyy')); 17 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 ('1001', '李志国', '男', '1985-09-26'); INSERT INTO `student` VALUES ('1002', '李甜甜', '女', '1987-02-06'); INSERT INTO `student` VALUES ('1003', '张小燕', '女', '1984-11-18'); INSERT INTO `student` VALUES ('1004', '王菲', '男', '1986-06-03'); INSERT INTO `student` VALUES ('1005', '杜宇', '女', '1986-04-25'); INSERT INTO `student` VALUES ('1006', '彭大生', '男', '1988-08-28'); INSERT INTO `student` VALUES ('1007', '王亮', '男', '1983-08-01'); INSERT INTO `student` VALUES ('1008', '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 ('1001', '2003', '企业管理'); INSERT INTO `course` VALUES ('1002', '2001', '马克思'); INSERT INTO `course` VALUES ('1003', '2002', 'OO&UML'); INSERT INTO `course` VALUES ('1004', '2004', '数据库'); INSERT INTO `course` VALUES ('1005', '2005', '英语'); INSERT INTO `course` VALUES ('1006', '2005', '大学语文'); INSERT INTO `course` VALUES ('1007', '2003', '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 ('1', '1001', '1', '87'); INSERT INTO `sc` VALUES ('2', '1001', '3', '66'); INSERT INTO `sc` VALUES ('3', '1001', '2', '77'); INSERT INTO `sc` VALUES ('4', '1001', '5', '45'); INSERT INTO `sc` VALUES ('5', '1001', '7', '67'); INSERT INTO `sc` VALUES ('6', '1002', '4', '26'); INSERT INTO `sc` VALUES ('7', '1002', '1', '86'); INSERT INTO `sc` VALUES ('8', '1003', '3', '67'); INSERT INTO `sc` VALUES ('9', '1003', '2', '97'); INSERT INTO `sc` VALUES ('10', '1003', '5', '67'); INSERT INTO `sc` VALUES ('11', '1004', '5', '78'); INSERT INTO `sc` VALUES ('12', '1004', '3', '67'); INSERT INTO `sc` VALUES ('13', '1004', '4', '49'); INSERT INTO `sc` VALUES ('14', '1005', '4', '76'); INSERT INTO `sc` VALUES ('15', '1005', '2', '84'); INSERT INTO `sc` VALUES ('16', '1005', '3', '35'); INSERT INTO `sc` VALUES ('17', '1006', '3', '54'); INSERT INTO `sc` VALUES ('18', '1006', '2', '76'); INSERT INTO `sc` VALUES ('19', '1006', '1', '56'); INSERT INTO `sc` VALUES ('20', '1007', '1', '56'); INSERT INTO `sc` VALUES ('21', '1007', '7', '88'); INSERT INTO `sc` VALUES ('22', '1007', '2', '89'); INSERT INTO `sc` VALUES ('23', '1007', '3', '57'); INSERT INTO `sc` VALUES ('24', '1007', '4', '99'); INSERT INTO `sc` VALUES ('25', '1007', '5', '85'); INSERT INTO `sc` VALUES ('26', '1008', '1', '76'); INSERT INTO `sc` VALUES ('27', '1008', '2', '44'); INSERT INTO `sc` VALUES ('28', '1008', '4', '87'); INSERT INTO `sc` VALUES ('29', '1008', '5', '33'); INSERT INTO `sc` VALUES ('30', '1002', '6', '65'); INSERT INTO `sc` VALUES ('31', '1002', '7', '90'); INSERT INTO `sc` VALUES ('32', '1006', '6', '67'); 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 ('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');
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#='001') a,(select s#,score from SC where C#='002') b where a.score>b.score and a.s#=b.s#;
-- mysql SELECT a.SId from (select SId,score from sc where CId='1') a,(select SId,score from sc where CId='2') 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#='001'and exists( Select * from SC SC_2 where SC_2.S#=SC.S# and SC_2.C#='002');
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#='002') score2 from Student,SC where Student.S#=SC.S# and C#='001') 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#='1001');
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#='1002') group by S# having count(*)=(select count(*) from SC where S#='1002');
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#,'002',(Select avg(score) from SC where C#='002') from Student where S# not in (Select S# from SC where C#='003')）;
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#='004') AS 数据库 ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理 ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='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 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# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1 ELSE 0 END) AS 企业管理平均分 ,100 * SUM(CASE WHEN C# = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '001' THEN 1 ELSE 0 END) AS 企业管理及格百分数 ,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 马克思平均分 ,100 * SUM(CASE WHEN C# = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '002' THEN 1 ELSE 0 END) AS 马克思及格百分数 ,SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/SUM(CASE C# WHEN '003' THEN 1 ELSE 0 END) AS UML平均分 ,100 * SUM(CASE WHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '003' THEN 1 ELSE 0 END) AS UML及格百分数 ,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1 ELSE 0 END) AS 数据库平均分 ,100 * SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '004' 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# = '001' LEFT JOIN SC AS T2 ON SC.S# = T2.S# AND T2.C# = '002' LEFT JOIN SC AS T3 ON SC.S# = T3.S# AND T3.C# = '003' LEFT JOIN SC AS T4 ON SC.S# = T4.S# AND T4.C# = '004' 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))='1981';
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# ;
