第一套题目

建表语句和数据

CREATE TABLE Student( Sno CHAR(3) PRIMARY KEY COMMENT "学号（主码）", Sname CHAR(8) NOT NULL COMMENT "学生姓名", Ssex CHAR(2) COMMENT"学生性别", Sbirthday DATETIME COMMENT "学生出生年月", Class CHAR(5) COMMENT"学生所在班级" ) CREATE TABLE Course( Cno CHAR(5) PRIMARY KEY COMMENT "课程号（主码）", Cname VARCHAR(10) COMMENT "课程名称", Tno CHAR(3) COMMENT "教工编号（外码）" ) CREATE TABLE Score( Sno CHAR(3) NOT NULL COMMENT "学号（外码）", Cno CHAR(5) NOT NULL COMMENT "课程号（外码）", Degree DECIMAL(4,1) COMMENT "成绩", PRIMARY KEY(Sno,Cno) ) CREATE TABLE Teacher( Tno CHAR(3) PRIMARY KEY NOT NULL COMMENT "教工编号（主码）", Tname CHAR(4) NOT NULL COMMENT "教工姓名", Tsex CHAR(2) NOT NULL COMMENT "教工姓名", Tbirthday DATETIME COMMENT "教工出生年月", Prof CHAR(6) COMMENT "职称", Depart VARCHAR(10) NOT NULL COMMENT "教工所在部门" ) '表（一）Student' INSERT INTO Student VALUES ('108','曾华','男','1977-09-01','95033'); INSERT INTO Student VALUES ('105','匡明','男','1975-10-02','95031'); INSERT INTO Student VALUES ('107','王丽','女','1976-01-23','95033'); INSERT INTO Student VALUES ('101','李军','男','1976-02-20','95033'); INSERT INTO Student VALUES ('109','王芳','女','1975-02-10','95032'); INSERT INTO Student VALUES ('103','陆军','男','1974-06-03','95031') INSERT INTO Student VALUES ('110','陆','男','1974-06-03','95031') '表（二）Course' INSERT INTO Course VALUES ('3-105','计算机导论','825'); INSERT INTO Course VALUES ('3-245','操作系统','804'); INSERT INTO Course VALUES ('3-166','数字电路','856'); INSERT INTO Course VALUES ('9-888','高等数学','831') '表（三）Score' INSERT INTO Score VALUES ('103','3-245','86'); INSERT INTO Score VALUES ('105','3-245','75'); INSERT INTO Score VALUES ('109','3-245','68'); INSERT INTO Score VALUES ('103','3-105','92'); INSERT INTO Score VALUES ('105','3-105','88'); INSERT INTO Score VALUES ('109','3-105','76'); INSERT INTO Score VALUES ('101','3-105','64'); INSERT INTO Score VALUES ('107','3-105','91'); INSERT INTO Score VALUES ('108','3-105','78'); INSERT INTO Score VALUES ('101','3-166','85'); INSERT INTO Score VALUES ('107','3-166','79'); INSERT INTO Score VALUES ('108','3-166','81'); '表（四）Teacher' INSERT INTO Teacher VALUES ('804','李诚','男','1958-12-02','副教授','计算机系'), ('856','张旭','男','1969-03-12','讲师','电子工程系'), ('825','王萍','女','1972-05-05','助教','计算机系'), ('831','刘冰','女','1977-08-14','助教','电子工程系')

题目

1、查询Student表中的所有记录的Sname、Ssex和Class列。 SELECT sname,ssex,class FROM student ; 2、查询教师所有的单位即不重复的Depart列。 SELECT depart FROM Teacher GROUP BY depart ; SELECT DISTINCT depart FROM Teacher ; 3、查询Student表的所有记录。 SELECT * FROM student ; 4、查询Score表中成绩在60到80之间的所有记录。 SELECT * FROM score WHERE degree BETWEEN 60 AND 80 ; 5、查询Score表中成绩为85，86或88的记录。 SELECT * FROM score WHERE degree=85 OR degree=86 OR degree=88 ; 6、查询Student表中“95031”班或性别为“女”的同学记录。 SELECT * FROM student WHERE class='95031' OR ssex='女' ; 7、以Class降序查询Student表的所有记录。 SELECT * FROM student ORDER BY class DESC ; 8、以Cno升序、Degree降序查询Score表的所有记录。 SELECT * FROM score ORDER BY cno,degree DESC ; 9、查询“95031”班的学生人数。 SELECT class,COUNT(*) FROM student GROUP BY class HAVING class='95031' ; 10、?查询Score表中的最高分的学生学号和课程号。（子查询或者排序） SELECT sno,cno FROM score ORDER BY degree DESC LIMIT 0,1 ; SELECT sno,cno FROM score WHERE degree IN (SELECT MAX(degree) FROM score ) ; 11、查询每门课的平均成绩。 SELECT cno,AVG(IFNULL(degree,0)) FROM score GROUP BY cno ; 12、查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。 SELECT cno, AVG(IFNULL(degree,0)) FROM score WHERE cno LIKE '3%' GROUP BY cno HAVING COUNT(*)>4 ; 13、查询分数大于70，小于90的Sno列。 SELECT sno FROM score WHERE degree>70 AND degree<90 ; 14、查询所有学生的Sname、Cno和Degree列。 SELECT stu.sname,sco.cno,sco.degree FROM student stu JOIN score sco ON stu.sno=sco.sno ORDER BY sco.cno ; 15、查询所有学生的Sno、Cname和Degree列。 SELECT stu.sno,cou.cname,sco.degree FROM student stu LEFT JOIN score sco ON stu.sno=sco.sno LEFT JOIN course cou ON sco.cno=cou.`Cno` ; 16、查询所有学生的Sname、Cname和Degree列。 SELECT stu.sname,cou.cname,sco.degree FROM student stu LEFT JOIN score sco ON stu.sno=sco.sno LEFT JOIN course cou ON sco.cno=cou.`Cno` ; 17、?查询“95033”班学生的平均分。 SELECT class,AVG(IFNULL(degree,0)) FROM student stu JOIN score sco ON stu.sno=sco.sno WHERE stu.class='95033' GROUP BY stu.class ; 18、 假设使用如下命令建立了一个grade表： CREATE TABLE grade(low INT(3),upp INT(3),rank CHAR(1)) INSERT INTO grade VALUES(90,100,'A'); INSERT INTO grade VALUES(80,89,'B'); INSERT INTO grade VALUES(70,79,'C'); INSERT INTO grade VALUES(60,69,'D'); INSERT INTO grade VALUES(0,59,'E') 现查询所有同学的Sno、Cno和rank列。 SELECT stu.sno,sco.cno,gra.rank FROM student stu JOIN grade gra JOIN score sco ON sco.sno=stu.sno WHERE sco.degree BETWEEN gra.low AND gra.upp ; SELECT t.tsno,t.tcno,gra.rank FROM grade gra JOIN ( SELECT stu.sno tsno,sco.cno tcno FROM student stu JOIN score sco ON stu.sno=sco.sno ) t ; SELECT s.sno,cno,g.rank FROM grade g ,(SELECT * FROM score ) s WHERE s.degree BETWEEN g.low AND g.upp 19、? 查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。 SELECT * FROM score WHERE cno='3-105' AND degree>( SELECT degree FROM score WHERE sno='109' AND cno='3-105' ) ; SELECT * FROM score WHERE cno='3-105' ; 20、查询score中选学多门课程的同学中分数为非最高分成绩的记录。 SELECT sno,cno,degree FROM score WHERE sno IN ( SELECT sno FROM score GROUP BY sno HAVING COUNT(*)>1 ) ORDER BY degree DESC LIMIT 1,20 ; SELECT s.* FROM score s JOIN ( SELECT sno FROM score GROUP BY sno HAVING COUNT(*)>1 ) t ON s.sno=t.sno WHERE s.degree<(SELECT MAX(degree) FROM score ) ; 21、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。 SELECT * FROM score sco JOIN ( SELECT degree FROM score WHERE sno='109' AND cno='3-105' ) sco1 ON sco.degree>sco1.degree ; SELECT * FROM score WHERE degree>( SELECT degree FROM score WHERE sno='109' AND cno='3-105' ) ; 22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列。 SELECT sno,sname,sbirthday FROM student WHERE YEAR(sbirthday)=( SELECT YEAR(sbirthday) FROM student WHERE sno='108' ) ; 23、查询“张旭“教师任课的学生成绩。 SELECT sco.* FROM score sco JOIN course cou ON sco.cno=cou.cno JOIN teacher tea ON cou.tno=tea.tno AND tea.tname='张旭' ; 24、查询选修某课程的同学人数多于5人的教师姓名。 SELECT tea.tname FROM course cou JOIN ( SELECT cno FROM score GROUP BY cno HAVING COUNT(*)>5 ) c ON cou.cno=c.cno JOIN teacher tea ON tea.tno=cou.tno ; 25、查询95033班和95031班全体学生的记录。 SELECT * FROM student WHERE class='95033' OR class='95031' ; 26、? 查询存在有85分以上成绩的课程Cno. SELECT cno FROM score WHERE degree>85 GROUP BY cno ; 27、查询出“计算机系“教师所教课程的成绩表。 SELECT sco.* FROM score sco JOIN course cou ON sco.cno=cou.cno JOIN teacher tea ON cou.tno=tea.tno AND tea.depart='计算机系' ; 28、查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。 (SELECT tname,prof FROM teacher WHERE prof NOT IN ( SELECT prof FROM teacher WHERE depart='计算机系')) UNION (SELECT tname,prof FROM teacher WHERE prof NOT IN ( SELECT prof FROM teacher WHERE depart='电子工程系' ) ) ; 29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。 SELECT * FROM score WHERE cno='3-105' AND degree>( SELECT MAX(degree) FROM score WHERE cno='3-245' ) ORDER BY degree DESC ; 30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree. SELECT * FROM score WHERE cno='3-105' AND degree>( SELECT MAX(degree) FROM score WHERE cno='3-245' ) ORDER BY degree ; 31、?查询所有教师和同学的name、sex和birthday. SELECT sname,ssex,Sbirthday FROM student UNION SELECT tname,tsex,Tbirthday FROM teacher ; 32、查询所有“女”教师和“女”同学的name、sex和birthday. SELECT sname,ssex,Sbirthday FROM student WHERE ssex='女' UNION SELECT tname,tsex,Tbirthday FROM teacher WHERE tsex='女' ; 33、?查询成绩比该课程平均成绩低的同学的成绩表。 SELECT sco.* FROM score sco JOIN ( SELECT cno,AVG(IFNULL(degree,0)) aaa FROM score GROUP BY cno) avgscore ON sco.cno=avgscore.cno WHERE sco.degree< avgscore.aaa ; 34、查询所有任课教师的Tname和Depart. SELECT DISTINCT tea.tname,tea.depart FROM score sco JOIN course cou ON sco.cno=cou.cno JOIN teacher tea ON cou.tno=tea.tno ; 35?、 查询所有未讲课的教师的Tname和Depart. SELECT tname,depart FROM teacher WHERE tname NOT IN ( SELECT tea.tname FROM score sco JOIN course cou ON sco.cno=cou.cno JOIN teacher tea ON cou.tno=tea.tno ) ; 36、查询至少有2名男生的班号。 SELECT class FROM student WHERE ssex='男' GROUP BY class HAVING COUNT(*)>1 ; 37、查询Student表中不姓“王”的同学记录。 SELECT * FROM student WHERE sname NOT LIKE '王%' ; 38、查询Student表中每个学生的姓名和年龄。 SELECT sname,YEAR(NOW())-YEAR(Sbirthday) FROM student ; 39、查询Student表中最大和最小的Sbirthday日期值。 SELECT MAX(Sbirthday),MIN(Sbirthday) FROM studnet ; 40、以班号和年龄从大到小的顺序查询Student表中的全部记录。 SELECT * FROM student ORDER BY class DESC,Sbirthday ; 41、查询“男”教师及其所上的课程。 SELECT tea.*,cou.cname FROM teacher tea JOIN course cou ON tea.tno=cou.tno AND tea.tsex='男' ; 42、查询最高分同学的Sno、Cno和Degree列。 SELECT *,MAX(degree) FROM score ; SELECT * FROM score WHERE degree=( SELECT MAX(degree) FROM score) ; 43、查询和“李军”同性别的所有同学的Sname. SELECT sname FROM student WHERE ssex=( SELECT ssex FROM student WHERE sname='李军') ; 44、查询和“李军”同性别并同班的同学Sname. SELECT sname FROM student stu JOIN( SELECT ssex,class FROM student WHERE sname='李军') t ON stu.ssex=t.ssex AND stu.class=t.class ; 45、查询所有选修“计算机导论”课程的“男”同学的成绩表。 SELECT sco.* FROM student stu JOIN score sco ON stu.sno=sco.sno JOIN course cou ON sco.cno=cou.cno WHERE stu.ssex='男' AND cou.cname='计算机导论' ;

第二套题目（sql基础20题）

一、

1./* 表1: Person +-------------+---------+ | 列名 | 类型 | +-------------+---------+ | PersonId | int | | FirstName | varchar | | LastName | varchar | +-------------+---------+ PersonId 是上表主键 表2: Address +-------------+---------+ | 列名 | 类型 | +-------------+---------+ | AddressId | int | | PersonId | int | | City | varchar | | State | varchar | +-------------+---------+ AddressId 是上表主键 编写一个 SQL 查询，满足条件：无论 person 是否有地址信息，都需要基于上述两表提供 person 的以下信息： FirstName, LastName, City, State */ select per.FirstName,per.LastName,add.city,add.state from person per full join address add on per.personid=add.personid ;

二、

2. /* 编写一个 SQL 查询，获取 Employee 表中第二高的薪水（Salary） 。 +----+--------+ | Id | Salary | +----+--------+ | 1 | 100 | | 2 | 200 | | 3 | 300 | +----+--------+ 例如上述 Employee 表，SQL查询应该返回 200 作为第二高的薪水。如果不存在第二高的薪水，那么查询应返回 null。 +---------------------+ | SecondHighestSalary | +---------------------+ | 200 | +---------------------+ */ -- 方法一： select ifnull(( select distinct salary from employee order by salary desc limit 1 offset 1),null) ; -- 方法二： select ( select distinct salary from employee order by salary desc limit 1 offset 1) ;

三

/* 编写一个 SQL 查询，获取 Employee 表中第 n 高的薪水（Salary）。 +----+--------+ | Id | Salary | +----+--------+ | 1 | 100 | | 2 | 200 | | 3 | 300 | +----+--------+ 例如上述 Employee 表，n = 2 时，应返回第二高的薪水 200。如果不存在第 n 高的薪水，那么查询应返回 null。 +------------------------+ | getNthHighestSalary(2) | +------------------------+ | 200 | +------------------------+ */ CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT BEGIN declare result int; set result=N-1; RETURN ( # Write your MySQL query statement below. select ifnull( ( select distinct salary from employee order by salary desc limit result,1 ) ,null) ); END

四