centos7 安装mysql

第一步、前往mysql官网下载所需的版本

Mysql5.7的rpm包下载地址为https://dev.mysql.com/downloads/mysql/ ，最好使用迅雷复制链接地址下载，具体方法：点击download，页面下方会显示 No thanks, just start my download.，一定要在此处右键，复制链接，在迅雷中下载。

下载完成后就上传的CentOS系统上。

第二步、解压安装

[root@youxi2 ~]# mkdir Mysql　　//创建一个专门的Mysql目录
[root@youxi2 ~]# tar xf mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar -C Mysql/　　//将解压的文件放到Mysql目录下
[root@youxi2 ~]# yum -y install make gcc-c++ cmake bison-devel ncurses-devel libaio libaio-devel net-tools　　//安装依赖包
由于CentOS7开始自带的数据库是mariadb，所以需要卸载系统中的mariadb组件，才能安装mysql的组件
[root@youxi2 ~]# rpm -qa | grep mariadb
mariadb-libs-5.5.60-1.el7_5.x86_64
[root@youxi2 ~]# yum -y remove mariadb-libs
　　现在开始安装mysql，由于依赖关系，所以顺序是固定的。
[root@youxi2 ~]# rpm -ivh Mysql/mysql-community-common-5.7.16-1.el7.x86_64.rpm
警告：Mysql/mysql-community-common-5.7.16-1.el7.x86_64.rpm: 头V3 DSA/SHA1 Signature, 密钥 ID 5072e1f5: NOKEY
准备中...                          ################################# [100%]
正在升级/安装...
 1:mysql-community-common-5.7.16-1.e################################# [100%]
[root@youxi2 ~]# rpm -ivh Mysql/mysql-community-libs-5.7.16-1.el7.x86_64.rpm
警告：Mysql/mysql-community-libs-5.7.16-1.el7.x86_64.rpm: 头V3 DSA/SHA1 Signature, 密钥 ID 5072e1f5: NOKEY
准备中...                          ################################# [100%]
正在升级/安装...
 1:mysql-community-libs-5.7.16-1.el7################################# [100%]
[root@youxi2 ~]# rpm -ivh Mysql/mysql-community-libs-compat-5.7.16-1.el7.x86_64.rpm
警告：Mysql/mysql-community-libs-compat-5.7.16-1.el7.x86_64.rpm: 头V3 DSA/SHA1 Signature, 密钥 ID 5072e1f5: NOKEY
准备中... ################################# [100%]
正在升级/安装...
1:mysql-community-libs-compat-5.7.1################################# [100%]
[root@youxi2 ~]# rpm -ivh Mysql/mysql-community-client-5.7.16-1.el7.x86_64.rpm
警告：Mysql/mysql-community-client-5.7.16-1.el7.x86_64.rpm: 头V3 DSA/SHA1 Signature, 密钥 ID 5072e1f5: NOKEY
准备中...                          ################################# [100%]
正在升级/安装...
 1:mysql-community-client-5.7.16-1.e################################# [100%]
[root@youxi2 ~]# rpm -ivh Mysql/mysql-community-server-5.7.16-1.el7.x86_64.rpm　　//之后安装就成功了
警告：Mysql/mysql-community-server-5.7.16-1.el7.x86_64.rpm: 头V3 DSA/SHA1 Signature, 密钥 ID 5072e1f5: NOKEY
准备中...                          ################################# [100%]
正在升级/安装...
 1:mysql-community-server-5.7.16-1.e################################# [100%]

第三步、启动mysql并设置开机自启

[root@youxi2 ~]# systemctl start mysqld
[root@youxi2 ~]# systemctl enable mysqld
[root@youxi2 ~]# systemctl status mysqld
● mysqld.service - MySQL Server
 Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
 Active: active (running) since 日 2019-06-02 12:11:34 CST; 45s ago
 Main PID: 7840 (mysqld)
 CGroup: /system.slice/mysqld.service
 └─7840 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid
​
6月 02 12:11:26 youxi2 systemd[1]: Starting MySQL Server...
6月 02 12:11:34 youxi2 systemd[1]: Started MySQL Server.

第四步、获取mysql临时密码，设置mysql的root用户密码

注意：5.6的密码使用 cat /root/.mysql_secret 查询

[root@youxi2 ~]# grep "password" /var/log/mysqld.log　　//前往日志文件查找临时密码
2019-06-02T04:11:28.935057Z 1 [Note] A temporary password is generated for root@localhost: zS+u&ro49wbo
[root@youxi2 ~]# mysql -uroot -p"zS+u&ro49wbo"
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.16
​
Copyright (c) 2000, 2016, 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.
//可以看到设置简单的密码是会报错的，具体原因看最后的扩展
mysql> alter user 'root'@'localhost' identified by '123456';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> alter user 'root'@'localhost' identified by 'root1234';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> alter user 'root'@'localhost' identified by 'root1234ABC';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> alter user 'root'@'localhost' identified by 'root1234ABCD!@#/pre>;
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
mysql> exit
Bye
　　修改密码出来使用“alter user 'root'@'localhost' identified by 'root1234ABCD!@#/pre>;”，也可以使用“set password for root@localhost=password('root1234ABCD!@#/pre>);”

第五步、测试

由于有特殊符号，必须用引号包裹密码

[root@youxi2 ~]# mysql -u root -p'root1234ABCD!@#/pre>
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.16 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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>

扩展：如果想要设置简单密码概如何操作？

有两种方法，一种在mysql里使用命令修改，一种直接修改配置文件。

在mysql里使用命令修改的办法：

[root@youxi2 ~]# mysql -u root -p'root1234ABCD!@'
​
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.16 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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> select @@validate_password_policy;　　//这个参数是密码复杂程度
+----------------------------+
| @@validate_password_policy |
+----------------------------+
| MEDIUM                     |
+----------------------------+
1 row in set (0.02 sec)
​
mysql> select @@validate_password_length;　　//这个参数是密码长度
+----------------------------+
| @@validate_password_length |
+----------------------------+
|                          8 |
+----------------------------+
1 row in set (0.00 sec)
mysql> set global validate_password_policy=0;　　//global全局的
Query OK, 0 rows affected (0.02 sec)
​
mysql> set global validate_password_length=1;
Query OK, 0 rows affected (0.00 sec)
​
mysql> set password for root@localhost=password('123');
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set password for root@localhost = password('1234');　　//设置密码
Query OK, 0 rows affected, 1 warning (0.00 sec)
​
mysql> flush privileges;　　//刷新
Query OK, 0 rows affected (0.00 sec)
​
mysql> exit　　//退出
Bye
​
[root@youxi2 ~]# mysql -uroot -p1234
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.16 MySQL Community Server (GPL)
​
Copyright (c) 2000, 2016, 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></pre>

说明：

1.validate_password_policy复杂度级别：0表示密码达到长度即可；1表示密码需达到长度，还需有数字、大小写字母（可以单一可以混合）以及特殊字符；2表示密码需达到长度，还需数字、大小写字母（可以单一可以混合）以及特殊字符字典文件。MEDIUM是中等，也就是1。

2.validate_password_length其实是一个动态的值，它的最小值等于validate_password_number_count+validate_password_special_char_count(2*validate_password_mixed_case_count)，而这三个参数分别对应密码中数字、特殊字符、大小写字母的最小数量。我操作时设置了validate_password_length=1，实际再次读取validate_password_length的值是4。

mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
|                          4 |
+----------------------------+
1 row in set (0.00 sec)</pre>

直接修改配置文件的办法：

[root@youxi2 ~]# vim /etc/my.cnf
validate-password=OFF　　//在[mysqld]模块内添加，将validate_password插件关闭
[root@youxi2 ~]# systemctl restart mysqld　　//重启mysqld服务
[root@youxi2 ~]# mysql -uroot -p1234    
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.16 MySQL Community Server (GPL)
​
Copyright (c) 2000, 2016, 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> set password for root@localhost=password('1');　　//validate_password插件关闭后密码长度只需大于等于1即可，复杂度没有要求
Query OK, 0 rows affected, 1 warning (0.00 sec)
​
mysql> flush privileges;　　//刷新
Query OK, 0 rows affected (0.00 sec)
​
mysql> exit　　//退出
Bye
[root@youxi2 ~]# mysql -uroot -p1
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.16 MySQL Community Server (GPL)
​
Copyright (c) 2000, 2016, 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></pre>

注意：Mysql5.7是自带validate_password插件，关闭后对密码没有复杂度要求，只需密码长度大于等于1。

建议：/etc/my.cnf中将默认字符集设置为utf8，即添加一行character_set_server=utf8，然后重启mysqld

博客地址：https://mrznan.github.io/blog/2019/09/08/linux/centos7%E4%B8%AD%E5%AE%89%E8%A3%85mysql/#more