mysql 练习

USE gg;
/*
CREATE TABLE STUDENT
(SNO VARCHAR(3) NOT NULL,
SNAME VARCHAR(4) NOT NULL,
SSEX VARCHAR(2) NOT NULL,
SBIRTHDAY DATETIME,
CLASS VARCHAR(5)) COLLATE='utf8_bin' ENGINE=InnoDB;

CREATE TABLE COURSE
(CNO VARCHAR(5) NOT NULL,
CNAME VARCHAR(10) NOT NULL,
TNO VARCHAR(10) NOT NULL) COLLATE='utf8_bin' ENGINE=InnoDB;

CREATE TABLE SCORE
(SNO VARCHAR(3) NOT NULL,
CNO VARCHAR(5) NOT NULL,
DEGREE NUMERIC(10, 1) NOT NULL) COLLATE='utf8_bin' ENGINE=InnoDB;

CREATE TABLE TEACHER
(TNO VARCHAR(3) NOT NULL,
TNAME VARCHAR(4) NOT NULL, TSEX VARCHAR(2) NOT NULL,
TBIRTHDAY DATETIME NOT NULL, PROF VARCHAR(6),
DEPART VARCHAR(10) NOT NULL) COLLATE='utf8_bin' ENGINE=InnoDB;

INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES ('108','曾华','男','1977-09-01',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES ('105','匡明','男','1975-10-02',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES ('107','王丽','女','1976-01-23',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES ('101','李军','男','1976-02-20',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES ('109','王芳','女','1975-02-10',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES ('103','陆君','男','1974-06-03',95031);
INSERT INTO COURSE(CNO,CNAME,TNO) VALUES ('3_105','计算机导论',825);
INSERT INTO COURSE(CNO,CNAME,TNO) VALUES ('3_245','操作系统',804);
INSERT INTO COURSE(CNO,CNAME,TNO) VALUES ('6_166','数据电路',856);
INSERT INTO COURSE(CNO,CNAME,TNO) VALUES ('9_888','高等数学',100);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('103','3_245',86);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('105','3_245',75);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('109','3_245',68);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('103','3_105',92);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('105','3_105',88);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('109','3_105',76);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('101','3_105',64);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('107','3_105',91);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('108','3_105',78);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('101','6_166',85);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('107','6_106',79);
INSERT INTO SCORE(SNO,CNO,DEGREE) VALUES ('108','6_166',81);
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES ('804','李诚','男','1958-12-02','副教授','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES ('856','张旭','男','1969-03-12','讲师','电子工程系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES ('825','王萍','女','1972-05-05','助教','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES ('831','刘冰','女','1977-08-14','助教','电子工程系');
*/

/*
-- 查询Student表中的所有记录的Sname、Ssex和Class列。
SELECT st.Sname,st.Ssex,st.Class
FROM STUDENT st;
--  查询教师所有的单位即不重复的Depart列。
SELECT  DISTINCT tt.DEPART
FROM TEACHER tt ;
-- 查询Student表的所有记录。
SELECT st.*
FROM STUDENT st;
-- 查询Score表中成绩在60到80之间的所有记录。
SELECT sc.*
FROM SCORE sc
WHERE sc.DEGREE >= 60 AND sc.DEGREE <=80 ORDER BY sc.SNO desc;

--  查询Score表中成绩为85，86或88的记录。
SELECT sc.*
FROM SCORE sc
WHERE sc.DEGREE in (85,86,88) ORDER BY sc.SNO desc;

-- 查询Student表中“95031”班或性别为“女”的同学记录。
SELECT st.*
FROM STUDENT st
WHERE st.CLASS = '95031' OR st.SSEX ='女'
ORDER BY st.SNO;

--  以Class降序查询Student表的所有记录。
SELECT st.*
FROM STUDENT st
ORDER BY st.CLASS DESC


-- 以Cno升序、Degree降序查询Score表的所有记录。
SELECT sc.*
FROM SCORE sc
ORDER BY sc.CNO ,sc.DEGREE DESC;


-- 查询“95031”班的学生人数。
SELECT COUNT(*)
FROM STUDENT st
WHERE st.CLASS='95031';


-- 查询Score表中的最高分的学生学号和课程号。
SELECT sc.SNO,sc.CNO
FROM SCORE sc
WHERE sc.DEGREE =
(
SELECT MAX(sc.DEGREE)
FROM SCORE sc
)
ORDER BY sc.SNO;


*/

-- 查询‘3-105’号课程的平均分。
SELECT AVG(sc.DEGREE)
FROM SCORE sc
WHERE sc.CNO='3_105'

*/


/*
-- 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 AVG(sc.DEGREE)
FROM SCORE sc
WHERE sc.CNO LIKE '3%' AND sc.CNO IN (
SELECT T.CNO
FROM (
SELECT COUNT(*) AS bb, sc.CNO
FROM SCORE sc
GROUP BY sc.CNO) T
WHERE T.bb >= 5)
GROUP BY sc.CNO
ORDER BY sc.CNO;



SELECT AVG(sc.DEGREE)
FROM SCORE sc
WHERE sc.CNO LIKE '3%' AND sc.CNO = (
SELECT T.CNO
FROM (
SELECT COUNT(*) AS BB,sc.CNO AS CNO
FROM SCORE sc
GROUP BY sc.CNO) T
WHERE T.BB >=5);



SELECT AVG(sc.DEGREE)
FROM SCORE sc
WHERE sc.CNO LIKE '3%'
GROUP BY sc.CNO
HAVING COUNT(sc.SNO) >=5;

*/

/*
-- 查询最低分大于70，最高分小于90的Sno列。
SELECT sc.SNO,sc.DEGREE
FROM SCORE sc
WHERE sc.DEGREE >70 AND sc.DEGREE < 90;


-- 查询所有学生的Sname、Cno和Degree列。
SELECT st.SNAME,sc.CNO,sc.DEGREE
FROM STUDENT st,SCORE sc
WHERE st.SNO=sc.SNO;

-- 查询所有学生的Sno、Cname和Degree列。
SELECT DISTINCT st.SNO,co.CNAME,sc.DEGREE
FROM STUDENT st,SCORE sc,COURSE co
WHERE st.SNO=sc.SNO AND sc.CNO= co.CNO
ORDER BY st.SNO

-- 查询所有学生的Sname、Cname和Degree列。
SELECT DISTINCT st.SNAME,co.CNAME,sc.DEGREE
FROM STUDENT st,COURSE co,SCORE sc
WHERE st.SNO=sc.SNO AND sc.CNO=co.CNO
ORDER BY st.SNAME;


-- 查询“95033”班所选课程的平均分。
SELECT AVG(sc.DEGREE)
FROM STUDENT st,SCORE sc
WHERE st.SNO=sc.SNO AND st.CLASS='95033';

-- 假设使用如下命令建立了一个grade表
create table grade(low   NUMERIC(10,0),upp   NUMERIC(10,0) ,rank   varchar(1) ) COLLATE='utf8_bin' ENGINE=INNODB;
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');
commit;


-- 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 DISTINCT st.*
FROM STUDENT st,SCORE sc
WHERE sc.CNO='3_105' AND sc.DEGREE > (
SELECT sc.DEGREE
FROM SCORE sc
WHERE sc.SNO='109' AND sc.CNO='3_105'
);
*/

/*
-- 查询score中选学一门以上课程的同学中分数为非最高分成绩的记录。

SELECT sc.*
FROM SCORE sc
WHERE sc.DEGREE < (SELECT MAX(sc.DEGREE) FROM SCORE sc)
GROUP by sc.CNO
HAVING COUNT(sc.SNO) >1;

-- 好像不对
*/

/*
-- 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 sc.*
FROM SCORE sc
WHERE sc.CNO='3_105' AND sc.DEGREE >(
SELECT sc.DEGREE
FROM SCORE sc
WHERE sc.CNO='3_105' AND sc.SNO='109');

*/

/*
-- 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。

set @birthday=(SELECT st.SBIRTHDAY FROM STUDENT st WHERE st.SNO='108');
SELECT st.SNO,st.SNAME,st.SBIRTHDAY
FROM STUDENT st
WHERE YEAR(st.SBIRTHDAY) = YEAR(@birthday);


-- 写法2
SELECT st.*
FROM STUDENT st
WHERE YEAR(st.SBIRTHDAY)=(SELECT YEAR(t.SBIRTHDAY) FROM STUDENT t WHERE t.SNO='108');
*/

/*
-- 查询“张旭“教师任课的学生成绩。

SELECT sc.*
FROM TEACHER te,SCORE sc,COURSE co
WHERE te.TNAME='张旭' AND te.TNO=co.TNO AND co.CNO=sc.CNO;
*/

/*
-- 查询选修某课程的同学人数多于5人的教师姓名。
SELECT DISTINCT te.TNAME
FROM TEACHER te,SCORE sc,COURSE co
WHERE te.TNO=co.TNO AND co.CNO=sc.CNO AND sc.CNO IN (
SELECT t.CNO
FROM (
SELECT COUNT(*) bb, sc.CNO
FROM SCORE sc
GROUP BY sc.CNO) T
WHERE T.bb >5);


SELECT DISTINCT te.TNAME
FROM TEACHER te,SCORE sc,COURSE co
WHERE te.TNO=co.TNO AND co.CNO=sc.CNO AND sc.CNO IN (
SELECT sc.CNO
FROM SCORE sc
GROUP BY sc.CNO
HAVING COUNT(sc.CNO) >5);

*/
/*
-- 查询95033班和95031班全体学生的记录。
SELECT DISTINCT st.*
FROM STUDENT st
WHERE  st.CLASS='95033' OR st.CLASS='95031'
ORDER BY st.SNO;
*/

/*
-- 查询存在有85分以上成绩的课程Cno.
SELECT DISTINCT sc.CNO
FROM SCORE sc
WHERE sc.DEGREE >85
ORDER BY sc.CNO;


SELECT sc.CNO
FROM SCORE sc
GROUP BY sc.CNO
HAVING MAX(sc.DEGREE)>85;

*/
/*
-- 查询出“计算机系“教师所教课程的成绩表。
SELECT sc.*
FROM SCORE sc,COURSE co,TEACHER te
WHERE te.DEPART='计算机系' AND te.TNO=co.TNO AND sc.CNO=co.CNO
ORDER BY sc.SNO;

SELECT sc.*
FROM SCORE sc JOIN (COURSE co,TEACHER te) ON co.TNO=te.TNO AND sc.CNO=co.CNO AND te.DEPART='计算机系'
ORDER BY sc.SNO;
*/

/*
-- 查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。
SELECT te.TNAME,te.PROF
FROM TEACHER te
WHERE te.DEPART='计算机系' AND te.PROF NOT IN (SELECT t.PROF FROM TEACHER t WHERE t.DEPART='电子工程系')
GROUP BY te.PROF;

*/

/*
-- 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 sc.CNO,sc.SNO,sc.DEGREE
FROM SCORE sc
WHERE sc.CNO='3_105' AND sc.DEGREE > (SELECT MAX(sc.DEGREE) FROM SCORE sc WHERE sc.CNO='3_245')
ORDER BY sc.DEGREE DESC;


-- 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 sc.CNO,sc.SNO,sc.DEGREE
FROM SCORE sc
WHERE sc.CNO='3_105' AND sc.DEGREE > (SELECT MAX(sc.DEGREE) FROM SCORE sc WHERE sc.CNO='3_245');

-- 查询所有教师和同学的name、sex和birthday.
SELECT st.SNAME name,st.SSEX,st.SBIRTHDAY
FROM STUDENT st UNION ALL
SELECT te.TNAME,te.TSEX,te.TBIRTHDAY
FROM TEACHER te;
*/

/*
-- 查询所有“女”教师和“女”同学的name、sex和birthday.
SELECT st.SNAME name,st.SSEX,st.SBIRTHDAY
FROM STUDENT st
WHERE st.SSEX='女' UNION ALL
SELECT te.TNAME,te.TSEX,te.TBIRTHDAY
FROM TEACHER te
WHERE te.TSEX='女';

*/

/*
-- 查询成绩比该课程平均成绩低的同学的成绩表。
--  写法1，查询每一科的平均分，再 根据要查询科目去取平局分比较
SELECT DISTINCT sc.*
FROM SCORE sc
WHERE sc.DEGREE < (SELECT T.bb FROM (SELECT AVG(DEGREE) bb,CNO FROM SCORE GROUP BY CNO) T WHERE T.CNO=sc.CNO)
ORDER BY CNO;

-- 写法2
SELECT DISTINCT sc.*
FROM SCORE sc
WHERE sc.DEGREE <( SELECT AVG(ss.DEGREE) FROM SCORE ss WHERE ss.CNO=sc.CNO )
ORDER BY sc.CNO;

*/
/*
-- 查询所有任课教师的Tname和Depart.
SELECT te.TNAME,te.DEPART
FROM TEACHER te,COURSE co
WHERE te.TNO=co.TNO;

SELECT te.TNAME,te.DEPART
FROM TEACHER te join COURSE USING(TNO);
*/

/*
-- 查询所有未讲课的教师的Tname和Depart.
SELECT te.TNAME,te.DEPART
FROM TEACHER te
WHERE  NOT EXISTS (SELECT sc.TNO FROM COURSE sc WHERE sc.TNO=te.TNO);
*/



/*
-- 查询至少有2名男生的班号。
-- 写法1
SELECT T.CLASS
FROM (
SELECT COUNT(*) BB,st.CLASS
FROM STUDENT st
WHERE st.SSEX='男'
GROUP BY st.CLASS) T
WHERE T.BB>=2;

-- 写法2
SELECT st.CLASS
FROM STUDENT st
WHERE st.SSEX='男'
GROUP BY st.CLASS
HAVING COUNT(st.SSEX) >1;
*/

/*
-- 查询Student表中不姓“王”的同学记录。
SELECT st.*
FROM STUDENT st
WHERE st.SNAME NOT LIKE '王%';

*/

/*
-- 查询Student表中每个学生的姓名和年龄。
-- 这条计算的准些
SELECT st.SNAME, st.SBIRTHDAY, ROUND(DATEDIFF(NOW(),st.SBIRTHDAY)/365) AGE
FROM STUDENT st;

-- 这条只做年的校验
SELECT SNAME,(YEAR(NOW())-YEAR(SBIRTHDAY)) AS AGE FROM STUDENT;

*/

/*
-- 查询Student表中最大和最小的Sbirthday日期值。
SELECT MIN(st.SBIRTHDAY) a, MAX(st.SBIRTHDAY) b
FROM STUDENT st;

-- 以班号和年龄从大到小的顺序查询Student表中的全部记录。
SELECT st.*
FROM STUDENT st
ORDER BY st.CLASS DESC,st.SBIRTHDAY ASC;
*/

/*
-- 查询“男”教师及其所上的课程。
SELECT co.CNAME,te.TNAME
FROM COURSE co,TEACHER te
WHERE te.TSEX='男' AND te.TNO=co.TNO;
-- 写法2
SELECT A.TNAME,B.CNAME FROM TEACHER A JOIN COURSE B USING(TNO) WHERE A.TSEX='男';
*/

/*
-- 查询最高分同学的Sno、Cno和Degree列。
SELECT sc.SNO,sc.CNO,sc.DEGREE
FROM SCORE sc
WHERE sc.DEGREE = (SELECT MAX(sc.DEGREE) FROM SCORE sc);

-- 查询和“李军”同性别的所有同学的Sname
SELECT st.SNAME
FROM STUDENT st
WHERE st.SSEX =(SELECT st.SSEX FROM STUDENT st WHERE st.SNAME='李军');

-- 查询和“李军”同性别并同班的同学Sname.
SELECT st.SNAME
FROM STUDENT st
WHERE st.SSEX =(SELECT st.SSEX FROM STUDENT st WHERE st.SNAME='李军') AND st.CLASS=(SELECT st.CLASS FROM STUDENT st WHERE st.SNAME='李军');

-- 查询所有选修“计算机导论”课程的“男”同学的成绩表

SELECT sc.*
FROM SCORE sc,STUDENT st,COURSE co
WHERE sc.SNO=st.SNO AND st.SSEX='男' AND co.CNO=sc.CNO AND co.CNAME='计算机导论'
ORDER BY sc.SNO;

-- 写法2
SELECT A.* FROM SCORE A JOIN (STUDENT B,COURSE C) USING(sno,CNO) WHERE B.SSEX='男' AND C.CNAME='计算机导论';
*/