2018-08-02Database13 分钟读完 (大约 1941 个字)

MySQL练习

There is recorded some MySQL pratices.

数据库和数据准备

数据库建立

 CREATE TABLE STUDENT
 (
SNO VARCHAR(3) NOT NULL,
SNAME VARCHAR(4) NOT NULL,
SSEX VARCHAR(2) NOT NULL,
SBIRTHDAY DATETIME,
CLASS VARCHAR(5)
 );

 CREATE TABLE COURSE
 (
CNO VARCHAR(5) NOT NULL,
CNAME VARCHAR(10) NOT NULL,
TNO VARCHAR(10) NOT NULL
 );

 CREATE TABLE SCORE
 (
SNO VARCHAR(3) NOT NULL,
CNO VARCHAR(5) NOT NULL,
DEGREE NUMERIC(10, 1) NOT NULL
 );

 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
 );

数据填充

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');

数据填充完成

mysql> SELECT * FROM STUDENT;
+-----+--------+------+---------------------+-------+
| SNO | SNAME  | SSEX | SBIRTHDAY           | CLASS |
+-----+--------+------+---------------------+-------+
| 108 | 曾华   | 男   | 1977-09-01 00:00:00 | 95033 |
| 105 | 匡明   | 男   | 1975-10-02 00:00:00 | 95031 |
| 107 | 王丽   | 女   | 1976-01-23 00:00:00 | 95033 |
| 101 | 李军   | 男   | 1976-02-20 00:00:00 | 95033 |
| 109 | 王芳   | 女   | 1975-02-10 00:00:00 | 95031 |
| 103 | 陆君   | 男   | 1974-06-03 00:00:00 | 95031 |
+-----+--------+------+---------------------+-------+
6 rows in set (0.00 sec)

mysql> SELECT * FROM COURSE;
+-------+-----------------+-----+
| CNO   | CNAME           | TNO |
+-------+-----------------+-----+
| 3-105 | 计算机导论      | 825 |
| 3-245 | 操作系统        | 804 |
| 6-166 | 数据电路        | 856 |
| 9-888 | 高等数学        | 100 |
+-------+-----------------+-----+
4 rows in set (0.00 sec)

mysql> SELECT * FROM SCORE;
+-----+-------+--------+
| SNO | CNO   | DEGREE |
+-----+-------+--------+
| 103 | 3-245 |   86.0 |
| 105 | 3-245 |   75.0 |
| 109 | 3-245 |   68.0 |
| 103 | 3-105 |   92.0 |
| 105 | 3-105 |   88.0 |
| 109 | 3-105 |   76.0 |
| 101 | 3-105 |   64.0 |
| 107 | 3-105 |   91.0 |
| 108 | 3-105 |   78.0 |
| 101 | 6-166 |   85.0 |
| 107 | 6-106 |   79.0 |
| 108 | 6-166 |   81.0 |
+-----+-------+--------+
12 rows in set (0.00 sec)

mysql> SELECT * FROM TEACHER;
+-----+--------+------+---------------------+-----------+-----------------+
| TNO | TNAME  | TSEX | TBIRTHDAY           | PROF      | DEPART          |
+-----+--------+------+---------------------+-----------+-----------------+
| 804 | 李诚   | 男   | 1958-12-02 00:00:00 | 副教授    | 计算机系        |
| 856 | 张旭   | 男   | 1969-03-12 00:00:00 | 讲师      | 电子工程系      |
| 825 | 王萍   | 女   | 1972-05-05 00:00:00 | 助教      | 计算机系        |
| 831 | 刘冰   | 女   | 1977-08-14 00:00:00 | 助教      | 电子工程系      |
+-----+--------+------+---------------------+-----------+-----------------+
4 rows in set (0.00 sec)

题目

查询STUDENT表中的所有记录的SNAME、SSEX和CLASS列

mysql> SELECT SNAME, SSEX, CLASS FROM STUDENT;
+--------+------+-------+
| SNAME  | SSEX | CLASS |
+--------+------+-------+
| 曾华   | 男   | 95033 |
| 匡明   | 男   | 95031 |
| 王丽   | 女   | 95033 |
| 李军   | 男   | 95033 |
| 王芳   | 女   | 95031 |
| 陆君   | 男   | 95031 |
+--------+------+-------+
6 rows in set (0.00 sec)

查询教师所有的单位即不重复的DEPART列

mysql> SELECT DEPART FROM TEACHER GROUP BY DEPART;
+-----------------+
| DEPART          |
+-----------------+
| 电子工程系      |
| 计算机系        |
+-----------------+
2 rows in set (0.00 sec)

查询STUDENT表的所有记录

mysql> SELECT * FROM STUDENT;
+-----+--------+------+---------------------+-------+
| SNO | SNAME  | SSEX | SBIRTHDAY           | CLASS |
+-----+--------+------+---------------------+-------+
| 108 | 曾华   | 男   | 1977-09-01 00:00:00 | 95033 |
| 105 | 匡明   | 男   | 1975-10-02 00:00:00 | 95031 |
| 107 | 王丽   | 女   | 1976-01-23 00:00:00 | 95033 |
| 101 | 李军   | 男   | 1976-02-20 00:00:00 | 95033 |
| 109 | 王芳   | 女   | 1975-02-10 00:00:00 | 95031 |
| 103 | 陆君   | 男   | 1974-06-03 00:00:00 | 95031 |
+-----+--------+------+---------------------+-------+
6 rows in set (0.00 sec)

查询SCORE表中成绩在60到80之间的所有记录

mysql> SELECT * FROM SCORE WHERE DEGREE BETWEEN 60 AND 80;
+-----+-------+--------+
| SNO | CNO   | DEGREE |
+-----+-------+--------+
| 105 | 3-245 |   75.0 |
| 109 | 3-245 |   68.0 |
| 109 | 3-105 |   76.0 |
| 101 | 3-105 |   64.0 |
| 108 | 3-105 |   78.0 |
| 107 | 6-106 |   79.0 |
+-----+-------+--------+
6 rows in set (0.00 sec)

查询SCORE表中成绩为85，86或88的记录

mysql> SELECT * FROM SCORE WHERE DEGREE IN(85, 86, 88);
+-----+-------+--------+
| SNO | CNO   | DEGREE |
+-----+-------+--------+
| 103 | 3-245 |   86.0 |
| 105 | 3-105 |   88.0 |
| 101 | 6-166 |   85.0 |
+-----+-------+--------+

查询STUDENT表中“95031”班或性别为“女”的同学记录

mysql> SELECT * FROM STUDENT WHERE CLASS='95031' OR SSEX='女';
+-----+--------+------+---------------------+-------+
| SNO | SNAME  | SSEX | SBIRTHDAY           | CLASS |
+-----+--------+------+---------------------+-------+
| 105 | 匡明   | 男   | 1975-10-02 00:00:00 | 95031 |
| 107 | 王丽   | 女   | 1976-01-23 00:00:00 | 95033 |
| 109 | 王芳   | 女   | 1975-02-10 00:00:00 | 95031 |
| 103 | 陆君   | 男   | 1974-06-03 00:00:00 | 95031 |
+-----+--------+------+---------------------+-------+
4 rows in set (0.00 sec)

以CLASS降序查询STUDENT表的所有记录

mysql> SELECT * FROM STUDENT ORDER BY CLASS DESC;
+-----+--------+------+---------------------+-------+
| SNO | SNAME  | SSEX | SBIRTHDAY           | CLASS |
+-----+--------+------+---------------------+-------+
| 108 | 曾华   | 男   | 1977-09-01 00:00:00 | 95033 |
| 107 | 王丽   | 女   | 1976-01-23 00:00:00 | 95033 |
| 101 | 李军   | 男   | 1976-02-20 00:00:00 | 95033 |
| 105 | 匡明   | 男   | 1975-10-02 00:00:00 | 95031 |
| 109 | 王芳   | 女   | 1975-02-10 00:00:00 | 95031 |
| 103 | 陆君   | 男   | 1974-06-03 00:00:00 | 95031 |
+-----+--------+------+---------------------+-------+
6 rows in set (0.00 sec)

以CNO升序、DEGREE降序查询SCORE表的所有记录

mysql> SELECT * FROM SCORE ORDER BY CNO, DEGREE DESC;
+-----+-------+--------+
| SNO | CNO   | DEGREE |
+-----+-------+--------+
| 103 | 3-105 |   92.0 |
| 107 | 3-105 |   91.0 |
| 105 | 3-105 |   88.0 |
| 108 | 3-105 |   78.0 |
| 109 | 3-105 |   76.0 |
| 101 | 3-105 |   64.0 |
| 103 | 3-245 |   86.0 |
| 105 | 3-245 |   75.0 |
| 109 | 3-245 |   68.0 |
| 107 | 6-106 |   79.0 |
| 101 | 6-166 |   85.0 |
| 108 | 6-166 |   81.0 |
+-----+-------+--------+
12 rows in set (0.00 sec)

查询“95031”班的学生人数

mysql> SELECT COUNT(*) FROM STUDENT WHERE CLASS='95031';
+----------+
| COUNT(*) |
+----------+
|        3 |
+----------+
1 row in set (0.00 sec)

查询SCORE表中的最高分的学生学号和课程号

mysql> SELECT SNO, CNO FROM SCORE WHERE DEGREE IN (SELECT MAX(DEGREE) FROM SCORE);
+-----+-------+
| SNO | CNO   |
+-----+-------+
| 103 | 3-105 |
+-----+-------+
1 row in set (0.00 sec)

查询‘3-105’号课程的平均分

mysql> SELECT AVG(DEGREE) FROM SCORE WHERE CNO='3-105';
+-------------+
| AVG(DEGREE) |
+-------------+
|    81.50000 |
+-------------+
1 row in set (0.00 sec)

查询SCORE表中至少有2名学生选修的并以3开头的课程的平均分数

mysql> SELECT AVG(DEGREE) FROM SCORE GROUP BY CNO HAVING COUNT(CNO)>1 AND CNO LIKE '3%';
+-------------+
| AVG(DEGREE) |
+-------------+
|    81.50000 |
|    76.33333 |
+-------------+
2 rows in set (0.00 sec)

查询最低分大于70，最高分小于90的SNO列

mysql> SELECT SNO FROM SCORE GROUP BY SNO HAVING MIN(DEGREE)>70 AND MAX(DEGREE)<90;
+-----+
| SNO |
+-----+
| 105 |
| 108 |
+-----+
2 rows in set (0.00 sec)

查询所有学生的SNAME、CNO和DEGREE列

mysql> SELECT A.SNAME, B.CNO, B.DEGREE FROM STUDENT A, SCORE B WHERE A.SNO=B.SNO;
+--------+-------+--------+
| SNAME  | CNO   | DEGREE |
+--------+-------+--------+
| 陆君   | 3-245 |   86.0 |
| 匡明   | 3-245 |   75.0 |
| 王芳   | 3-245 |   68.0 |
| 陆君   | 3-105 |   92.0 |
| 匡明   | 3-105 |   88.0 |
| 王芳   | 3-105 |   76.0 |
| 李军   | 3-105 |   64.0 |
| 王丽   | 3-105 |   91.0 |
| 曾华   | 3-105 |   78.0 |
| 李军   | 6-166 |   85.0 |
| 王丽   | 6-106 |   79.0 |
| 曾华   | 6-166 |   81.0 |
+--------+-------+--------+
12 rows in set (0.00 sec)
# 解法二使用内连接
mysql> SELECT STUDENT.SNAME, SCORE.CNO, SCORE.DEGREE FROM STUDENT INNER JOIN SCORE ON STUDENT.SNO=SCORE.SNO;
+--------+-------+--------+
| SNAME  | CNO   | DEGREE |
+--------+-------+--------+
| 陆君   | 3-245 |   86.0 |
| 匡明   | 3-245 |   75.0 |
| 王芳   | 3-245 |   68.0 |
| 陆君   | 3-105 |   92.0 |
| 匡明   | 3-105 |   88.0 |
| 王芳   | 3-105 |   76.0 |
| 李军   | 3-105 |   64.0 |
| 王丽   | 3-105 |   91.0 |
| 曾华   | 3-105 |   78.0 |
| 李军   | 6-166 |   85.0 |
| 王丽   | 6-106 |   79.0 |
| 曾华   | 6-166 |   81.0 |
+--------+-------+--------+
12 rows in set (0.00 sec)

查询所有学生的SNO、CNAME和DEGREE列

mysql> SELECT A.SNO, B.CNAME, A.DEGREE FROM SCORE A, COURSE B WHERE A.CNO=B.CNO;
+-----+-----------------+--------+
| SNO | CNAME           | DEGREE |
+-----+-----------------+--------+
| 103 | 操作系统        |   86.0 |
| 105 | 操作系统        |   75.0 |
| 109 | 操作系统        |   68.0 |
| 103 | 计算机导论      |   92.0 |
| 105 | 计算机导论      |   88.0 |
| 109 | 计算机导论      |   76.0 |
| 101 | 计算机导论      |   64.0 |
| 107 | 计算机导论      |   91.0 |
| 108 | 计算机导论      |   78.0 |
| 101 | 数据电路        |   85.0 |
| 108 | 数据电路        |   81.0 |
+-----+-----------------+--------+
11 rows in set (0.01 sec)

# 解法二使用内连接
mysql> SELECT A.SNO, C.CNAME, B.DEGREE FROM STUDENT A INNER JOIN SCORE B INNER JOIN COURSE C ON A.SNO=B.SNO AND B.CNO=C.CNO;
+-----+-----------------+--------+
| SNO | CNAME           | DEGREE |
+-----+-----------------+--------+
| 108 | 计算机导论      |   78.0 |
| 108 | 数据电路        |   81.0 |
| 105 | 操作系统        |   75.0 |
| 105 | 计算机导论      |   88.0 |
| 107 | 计算机导论      |   91.0 |
| 101 | 计算机导论      |   64.0 |
| 101 | 数据电路        |   85.0 |
| 109 | 操作系统        |   68.0 |
| 109 | 计算机导论      |   76.0 |
| 103 | 操作系统        |   86.0 |
| 103 | 计算机导论      |   92.0 |
+-----+-----------------+--------+
11 rows in set (0.00 sec)

查询所有学生的SNAME、CNAME和DEGREE列

mysql> SELECT A.SNAME, B.CNAME, C.DEGREE FROM STUDENT A, COURSE B, SCORE C WHERE A.SNO=C.SNO AND B.CNO=C.CNO;
+--------+-----------------+--------+
| SNAME  | CNAME           | DEGREE |
+--------+-----------------+--------+
| 曾华   | 计算机导论      |   78.0 |
| 曾华   | 数据电路        |   81.0 |
| 匡明   | 操作系统        |   75.0 |
| 匡明   | 计算机导论      |   88.0 |
| 王丽   | 计算机导论      |   91.0 |
| 李军   | 计算机导论      |   64.0 |
| 李军   | 数据电路        |   85.0 |
| 王芳   | 操作系统        |   68.0 |
| 王芳   | 计算机导论      |   76.0 |
| 陆君   | 操作系统        |   86.0 |
| 陆君   | 计算机导论      |   92.0 |
+--------+-----------------+--------+
11 rows in set (0.00 sec)

# 解法二内连接
mysql> SELECT STUDENT.SNAME, COURSE.CNAME, SCORE.DEGREE FROM STUDENT INNER JOIN SCORE INNER JOIN COURSE ON STUDENT.SNO=SCORE.SNO AND SCORE.CNO=COURSE.CNO;
+--------+-----------------+--------+
| SNAME  | CNAME           | DEGREE |
+--------+-----------------+--------+
| 曾华   | 计算机导论      |   78.0 |
| 曾华   | 数据电路        |   81.0 |
| 匡明   | 操作系统        |   75.0 |
| 匡明   | 计算机导论      |   88.0 |
| 王丽   | 计算机导论      |   91.0 |
| 李军   | 计算机导论      |   64.0 |
| 李军   | 数据电路        |   85.0 |
| 王芳   | 操作系统        |   68.0 |
| 王芳   | 计算机导论      |   76.0 |
| 陆君   | 操作系统        |   86.0 |
| 陆君   | 计算机导论      |   92.0 |
+--------+-----------------+--------+
11 rows in set (0.00 sec)

查询“95033”班所选课程的平均分

mysql> SELECT AVG(DEGREE) FROM SCORE INNER JOIN STUDENT S ON S.CLASS='95033';
+-------------+
| AVG(DEGREE) |
+-------------+
|    80.25000 |
+-------------+
1 row in set (0.00 sec)

# 解法二
mysql> mysql> SELECT AVG(DEGREE) FRO WHERE SNO IN(SELECT SNO FROM STUDENT WHERE CLASS='95033');
+-------------+
| AVG(DEGREE) |
+-------------+
|    79.66667 |
+-------------+
1 row in set (0.00 sec)

假设使用如下命令建立了一个grade表

CREATE TABLE grade(low int,upp int,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');

查询所有同学的SNO、CNO和rank列

mysql> SELECT A.SNO, A.CNO, B.rank FROM SCORE A, grade B WHERE A.DEGREE BETWEEN low and upp;
+-----+-------+------+
| SNO | CNO   | rank |
+-----+-------+------+
| 103 | 3-245 | B    |
| 105 | 3-245 | C    |
| 109 | 3-245 | D    |
| 103 | 3-105 | A    |
| 105 | 3-105 | B    |
| 109 | 3-105 | C    |
| 101 | 3-105 | D    |
| 107 | 3-105 | A    |
| 108 | 3-105 | C    |
| 101 | 6-166 | B    |
| 107 | 6-106 | C    |
| 108 | 6-166 | B    |
+-----+-------+------+
12 rows in set (0.00 sec)

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

mysql> SELECT * FROM STUDENT WHERE SNO IN (SELECT SNO FROM SCORE WHERE CNO='3-105' AND DEGREE>(SELECT DEGREE FROM SCORE WHERE SNO='109' AND CNO='3-105'));
+-----+--------+------+---------------------+-------+
| SNO | SNAME  | SSEX | SBIRTHDAY           | CLASS |
+-----+--------+------+---------------------+-------+
| 103 | 陆君   | 男   | 1974-06-03 00:00:00 | 95031 |
| 105 | 匡明   | 男   | 1975-10-02 00:00:00 | 95031 |
| 107 | 王丽   | 女   | 1976-01-23 00:00:00 | 95033 |
| 108 | 曾华   | 男   | 1977-09-01 00:00:00 | 95033 |
+-----+--------+------+---------------------+-------+
4 rows in set (0.00 sec)

查询”95033”班和”95031”班全体学生的记录

mysql> SELECT * FROM STUDENT WHERE CLASS IN('95033', '95031');
+-----+--------+------+---------------------+-------+
| SNO | SNAME  | SSEX | SBIRTHDAY           | CLASS |
+-----+--------+------+---------------------+-------+
| 108 | 曾华   | 男   | 1977-09-01 00:00:00 | 95033 |
| 105 | 匡明   | 男   | 1975-10-02 00:00:00 | 95031 |
| 107 | 王丽   | 女   | 1976-01-23 00:00:00 | 95033 |
| 101 | 李军   | 男   | 1976-02-20 00:00:00 | 95033 |
| 109 | 王芳   | 女   | 1975-02-10 00:00:00 | 95031 |
| 103 | 陆君   | 男   | 1974-06-03 00:00:00 | 95031 |
+-----+--------+------+---------------------+-------+
6 rows in set (0.00 sec)

查询存在有85分以上成绩的课程CNO

mysql> SELECT CNO FROM SCORE GROUP BY CNO HAVING CNO IN (SELECT CNO FROM SCORE WHERE DEGREE>85);
+-------+
| CNO   |
+-------+
| 3-105 |
| 3-245 |
+-------+
2 rows in set (0.00 sec)

查询出“计算机系“教师所教课程的成绩表

mysql> SELECT * FROM SCORE WHERE CNO IN(SELECT CNO FROM COURSE WHERE TNO IN(SELECT TNO FROM TEACHER WHERE DEPART='计算机系'));
+-----+-------+--------+
| SNO | CNO   | DEGREE |
+-----+-------+--------+
| 103 | 3-245 |   86.0 |
| 105 | 3-245 |   75.0 |
| 109 | 3-245 |   68.0 |
| 103 | 3-105 |   92.0 |
| 105 | 3-105 |   88.0 |
| 109 | 3-105 |   76.0 |
| 101 | 3-105 |   64.0 |
| 107 | 3-105 |   91.0 |
| 108 | 3-105 |   78.0 |
+-----+-------+--------+
9 rows in set (0.00 sec)
# 解法二
mysql> SELECT * FROM SCORE WHERE CNO IN(SELECT C.CNO FROM TEACHER T, COURSE C WHERE T.DEPART='计算机系' AND T.TNO=C.TNO);
+-----+-------+--------+
| SNO | CNO   | DEGREE |
+-----+-------+--------+
| 103 | 3-245 |   86.0 |
| 105 | 3-245 |   75.0 |
| 109 | 3-245 |   68.0 |
| 103 | 3-105 |   92.0 |
| 105 | 3-105 |   88.0 |
| 109 | 3-105 |   76.0 |
| 101 | 3-105 |   64.0 |
| 107 | 3-105 |   91.0 |
| 108 | 3-105 |   78.0 |
+-----+-------+--------+
9 rows in set (0.00 sec)

本文标题：MySQL练习
本文作者：Thomas Woo
发布时间：2018-08-02 18:00
最后更新：2020-06-20 15:40
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