mysql安装及基本操作（mysql作业）

1 官网下载，链接  https://www.mysql.com/downloads/

Download MySQL Community Server

默认为你选好了Mac OS X 平台

选择的是.dmg的。点击右侧的download进行下载。

跳转到另外一个界面，提示你需不需要注册，直接选择最下面的“No thanks,just take me to downloads!”

2  安装MySQL

安装完成后终端输入：

$mysql -version

-bash: mysql: command not found

”/usr/local/mysql/bin/mysql”为mysql默认安装路径：

$/usr/local/mysql/bin/mysql -version

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

$cd /usr/local/bin

$sudo ln -fs  /usr/local/mysql/bin/mysql  mysql

Password:

$mysql  -version

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

配置root账号的密码，默认没有配置，

$ mysql -u root

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3

Server version: 5.7.18 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, 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>

mysql>update mysql.user  set  authentication_string = password('******') where user ='root';

Query OK, 1 row affected, 1 warning (0.00 sec)

Rows matched: 1  Changed: 1  Warnings: 1

mysql> flush privileges;

mysql> quit

flush privileges后mysql -u root就登录不上了，需要用密码了例如下面

$mysql -u root

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

mysql -u root -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 5

Server version: 5.7.18 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, 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> create database homework;

ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

出现这样的报错，解决办法：重新设置一遍密码

mysql> set password =password('******');

Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> create database homework;

Query OK, 1 row affected (0.00 sec)

mysql> use homework;

Database changed

mysql> show tables;

Empty set (0.00 sec)

数据库的基本操作，创建数据库。

mysql> create table Student(Sno int(10),Sname varchar(255),Ssex varchar(255),Sage int(10),Sdept varchar(255));

Query OK, 0 rows affected (0.03 sec)

mysql> show tables;

+--------------------+

| Tables_in_homework |

+--------------------+

| Student            |

+--------------------+

1 row in set (0.00 sec)

查看创建表的信息语句：

mysql> show create table Student;

+---------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Table   | Create Table                                                                                                                                                                                                                              |

+---------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Student | CREATE TABLE `Student` (

`Sno` int(10) DEFAULT NULL,

`Sname` varchar(255) DEFAULT NULL,

`Ssex` varchar(255) DEFAULT NULL,

`Sage` int(10) DEFAULT NULL,

`Sdept` varchar(255) DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1 |

+---------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

1 row in set (0.02 sec)

mysql> create table Course(Con int(10),Cname varchar(255),Cpno int(10),Ccredit int(10));

Query OK, 0 rows affected (0.03 sec)

mysql> show create table Course;

+--------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Table  | Create Table                                                                                                                                                                                      |

+--------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Course | CREATE TABLE `Course` (

`Con` int(10) DEFAULT NULL,

`Cname` varchar(255) DEFAULT NULL,

`Cpno` int(10) DEFAULT NULL,

`Ccredit` int(10) DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1 |

+--------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

插入一条数据：

mysql> insert into Course values('4','data structure','7','4');

Query OK, 1 row affected (0.00 sec)

更新一条数据：

mysql> update Course set Cno='5' where Cname='data structure';

ERROR 1054 (42S22): Unknown column 'Cno' in 'field list'

发现创建的字段应该是Cno，创建错了，成Con

更改字段:

mysql> alter table Course change Con Cno int(10);

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0

mysql> update Course set Cno='5' where Cname='data structure';

Query OK, 1 row affected (0.01 sec)

Rows matched: 1  Changed: 1  Warnings: 0

查询数据：

mysql> select * from Course;

+------+--------------------+------+---------+

| Cno  | Cname              | Cpno | Ccredit |

+------+--------------------+------+---------+

|    1 | database           |    5 |       4 |

|    2 | math               |    0 |       2 |

|    3 | information system |    1 |       4 |

|    4 | operation  system  |    6 |       3 |

|    5 | data structure     |    7 |       4 |

|    6 | data process       |    0 |       2 |

|    7 | pascal             |    6 |       4 |

+------+--------------------+------+---------+

7 rows in set (0.00 sec)