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/get/Downloads/MySQL-5.7/mysql-5.7.26-1.el7.x86_64.rpm-bundle.tar
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
[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!@#$'; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.01 sec) mysql> exit Bye
修改密码出来使用“alter user 'root'@'localhost' identified by 'root1234ABCD!@#$';”，也可以使用“set password for root@localhost=password('root1234ABCD!@#$');”
第五步、测试
由于有特殊符号，必须用引号包裹密码
[root@youxi2 ~]# mysql -u root -p'root1234ABCD!@#$' 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>
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)
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>
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