mysql学习03

Posted 2021-01-10 独孤_败天

https://www.cnblogs.com/wupeiqi/articles/5729934.html

 

https://www.cnblogs.com/wupeiqi/articles/5748496.html

mysql测试题

一、表关系

请创建如下表，并创建相关约束

Microsoft Windows [版本 10.0.14393]
(c) 2016 Microsoft Corporation。保留所有权利。

C:\\Users\\Administrator>mysql -u root -P3306 -h 127.0.0.1
ERROR 1045 (28000): Access denied for user \'root\'@\'localhost\' (using password: NO)

C:\\Users\\Administrator>mysql -u root -P3306 -h 127.0.0.1 -p
Enter password: ******
Welcome to the MySQL monitor.  Commands end with ; or \\g.
Your MySQL connection id is 2
Server version: 5.5.13 MySQL Community Server (GPL)

Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type \'help;\' or \'\\h\' for help. Type \'\\c\' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| kaige              |
| mysql              |
| performance_schema |
| runbs              |
| sdhz               |
| sunck              |
| test               |
+--------------------+
8 rows in set (0.17 sec)

mysql> create database sql_test
    -> ;
Query OK, 1 row affected (0.07 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| kaige              |
| mysql              |
| performance_schema |
| runbs              |
| sdhz               |
| sql_test           |
| sunck              |
| test               |
+--------------------+
9 rows in set (0.00 sec)

mysql> use sql_test;
Database changed
mysql> drop database sql_test;
Query OK, 0 rows affected (0.21 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| kaige              |
| mysql              |
| performance_schema |
| runbs              |
| sdhz               |
| sunck              |
| test               |
+--------------------+
8 rows in set (0.00 sec)

mysql> create database sql_test default charset utf-8 collate utf8_general_ci;
ERROR 1115 (42000): Unknown character set: \'utf\'
mysql> create database sql_test default charset utf8 collate utf8_general_ci;
Query OK, 1 row affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| kaige              |
| mysql              |
| performance_schema |
| runbs              |
| sdhz               |
| sql_test           |
| sunck              |
| test               |
+--------------------+
9 rows in set (0.00 sec)

mysql> use sql_test;
Database changed
mysql> show tables;
Empty set (0.05 sec)

mysql> create table class(
    -> cid int not null auto_increment primary key,
    -> caption varchar(25)
    -> )engine=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.16 sec)

mysql> show tables;
+--------------------+
| Tables_in_sql_test |
+--------------------+
| class              |
+--------------------+
1 row in set (0.00 sec)

mysql> desr class
    -> ;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'desr class\' at line 1
mysql> desc class;
+---------+-------------+------+-----+---------+----------------+
| Field   | Type        | Null | Key | Default | Extra          |
+---------+-------------+------+-----+---------+----------------+
| cid     | int(11)     | NO   | PRI | NULL    | auto_increment |
| caption | varchar(25) | YES  |     | NULL    |                |
+---------+-------------+------+-----+---------+----------------+
2 rows in set (0.09 sec)

mysql> create table teacher(
    -> tid int auto_increment primary key not null,
    -> tname varchar(25),
    -> )engine=InnoDB default charset=utf8;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \')engine=InnoDB default charset=utf8\' at line 4
mysql> create table teacher(
    -> tid int auto_increment primary key not null,
    -> tname varchar(25)
    -> )engine=InnoDB default charset=utf8;
Query OK, 0 rows affected (0.11 sec)

mysql> desc teacher
    -> ;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| tid   | int(11)     | NO   | PRI | NULL    | auto_increment |
| tname | varchar(25) | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
2 rows in set (0.01 sec)

mysql> create table student(
    -> sid int auto_increment primary key not null,
    -> sname varchar(25),
    -> gender varchar(2),
    -> class_id int
    -> )engine=InnoDB default charset=utf8;
Query OK, 0 rows affected (0.09 sec)

mysql> alter table class add constraint FK_class_student foreign key class.cid references student.class_id;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'references student.class_id\' at line 1
mysql> show tables;
+--------------------+
| Tables_in_sql_test |
+--------------------+
| class              |
| student            |
| teacher            |
+--------------------+
3 rows in set (0.00 sec)

mysql> desc student;
+----------+-------------+------+-----+---------+----------------+
| Field    | Type        | Null | Key | Default | Extra          |
+----------+-------------+------+-----+---------+----------------+
| sid      | int(11)     | NO   | PRI | NULL    | auto_increment |
| sname    | varchar(25) | YES  |     | NULL    |                |
| gender   | varchar(2)  | YES  |     | NULL    |                |
| class_id | int(11)     | YES  |     | NULL    |                |
+----------+-------------+------+-----+---------+----------------+
4 rows in set (0.01 sec)

mysql> desc class;
+---------+-------------+------+-----+---------+----------------+
| Field   | Type        | Null | Key | Default | Extra          |
+---------+-------------+------+-----+---------+----------------+
| cid     | int(11)     | NO   | PRI | NULL    | auto_increment |
| caption | varchar(25) | YES  |     | NULL    |                |
+---------+-------------+------+-----+---------+----------------+
2 rows in set (0.01 sec)

mysql> alter table student add constraint fk_stu_cls foreign key student(class_id) references class(cid);
Query OK, 0 rows affected (0.38 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> desc student;
+----------+-------------+------+-----+---------+----------------+
| Field    | Type        | Null | Key | Default | Extra          |
+----------+-------------+------+-----+---------+----------------+
| sid      | int(11)     | NO   | PRI | NULL    | auto_increment |
| sname    | varchar(25) | YES  |     | NULL    |                |
| gender   | varchar(2)  | YES  |     | NULL    |                |
| class_id | int(11)     | YES  | MUL | NULL    |                |
+----------+-------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)

mysql> create table student(
    -> sid int not null primary key auto_increment,
    -> sname varchar(25),
    -> gender varchar(25),
    -> class_id;;;;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'\' at line 5
ERROR:
No query specified

ERROR:
No query specified

ERROR:
No query specified

mysql> create table course9
    -> create table course9；；
    ->
    -> ‘
    -> ；
    ->
    -> );
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'create table course9????

??
??

)\' at line 2
mysql> create table course(
    -> cid int not null primary key auto_increment,
    -> cname varchar(25),
    -> tearch_id int
    -> )engine=InnoDB default charset=utf8;
Query OK, 0 rows affected (0.09 sec)

mysql> alter table course add constraint fk_cour_teach foreign key course(tearch_id) references teacher(tid);
Query OK, 0 rows affected (0.16 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> create table score(
    -> sid int not null primary key auto_increment,
    -> student_id int not null,
    -> corse_id int not null,
    -> number int not null
    -> )engine=InnoDB default charset=utf8;
Query OK, 0 rows affected (0.13 sec)

mysql> alter table score add constraint score_to_stu foreign key score(student_id) references student(sid);
Query OK, 0 rows affected (0.23 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> alter table score add constraint score_to_corse foreign key score(corse_id) references course(cid);
Query OK, 0 rows affected (0.45 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql>

创建语句

 

mysql> select
    -> *
    -> from
    -> score
    -> left join student on score.student_id=student.sid
    -> left join course on score.corse_id=course.cid;
+-----+------------+----------+--------+------+-------+--------+----------+------+---------+-----------+
| sid | student_id | corse_id | number | sid  | sname | gender | class_id | cid  | cname   | tearch_id |
+-----+------------+----------+--------+------+-------+--------+----------+------+---------+-----------+
|   1 |          1 |        1 |     60 |    1 | may   | nv     |        1 |    1 | shengwu |         1 |
|   2 |          1 |        2 |     59 |    1 | may   | nv     |        1 |    2 | tiyu    |         1 |
|   3 |          2 |        2 |    100 |    2 | tom   | na     |        1 |    2 | tiyu    |         1 |
+-----+------------+----------+--------+------+-------+--------+----------+------+---------+-----------+
3 rows in set (0.06 sec)

mysql> select
    -> score.sid,
    -> score.student_id,
    -> student.sname,
    -> score.corse_id,
    -> course.cname,
    -> score.name
    -> from
    -> left join student on score.student_idIOS开发－OC学习－常用功能代码片段整理

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