第一步：Cenos7之后都默认安装的是MariaDB，直接安装MySQL会出现冲突，所以先查找出已安装的MariaDB
rpm -qa | grep mariadb
第二步：删除旧版本mariadb
[root@ShuaiJhou ~]# yum -y remove mariadb*
[root@ShuaiJhou ~]# rpm -qa | grep mariadb
[root@ShuaiJhou ~]#
或
nodeps代表强制，后面跟刚才查询出来的结果，移除之后可以再用上一条命令检验
rpm -e --nodeps mariadb-libs-5.5.52-1.el7.x86_64
第三步：yum 安装MySQL 5.7的方法
1.下载MYSQL5.7包
wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
2.再安装MYSQL源
[root@ShuaiJhou ~]# rpm -ivh mysql57-community-release-el7-11.noarch.rpm
[root@ShuaiJhou ~]# yum list
3.yum安装MYSQL
[root@ShuaiJhou ~]# yum -y install mysql-community-server
[root@ShuaiJhou ~]# systemctl start mysqld #启动MySQL会生成临时密码
第四步：启动MySQL服务并设置开机自启动
[root@ShuaiJhou ~]# systemctl start mysqld
[root@ShuaiJhou ~]# systemctl enable mysqld
第五步：获取自动生成的MySQL密码，并进入MySQL
[root@ShuaiJhou ~]# grep 'temporary password' /var/log/mysqld.log
温馨提示：
第六步：进入必须先修改密码。否则什么都做不了。mysql5.7默认安装了密码安全检查插件（validate_password），默认密码检查策略要求密码必须包含：大小写字母、数字和特殊符号，并且长度不能少于8位。否则会提示ERROR 1819 (HY000): Your password does not satisfy the current policy requirements错误，如下图所示：
温馨提示： 如果想设置简单密码，如下操作：
方法一：首先，修改validate_password_policy参数的值
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.03 sec)
定义复杂度的级别：
0：只检查长度。
1：检查长度、数字、大小写、特殊字符。
2：检查长度、数字、大小写、特殊字符字典文件
mysql> set global validate_password_length=1; #定义长度 默认是8位数修改为1后密码长度>=4位数
Query OK, 0 rows affected (0.01 sec)
[root@ShuaiJhou ~]# mysql -uroot -p'k;tGXz>XF4AC'
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: 5.7.26
Copyright (c) 2000, 2019, 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> ALTER USER 'root'@'localhost' IDENTIFIED BY '123';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set global validate_password_length=0;
Query OK, 0 rows affected (0.00 sec)
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '1234';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
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 '12345678';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set global validate_password_length=1;
Query OK, 0 rows affected (0.00 sec)
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '1234';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.00 sec)
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '1234789';
Query OK, 0 rows affected (0.00 sec)
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '12345678';
Query OK, 0 rows affected (0.00 sec)
mysql> set password for root@localhost = password('123456');
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> exit
Bye
[root@ShuaiJhou ~]# mysql -uroot -p123456
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: 5.7.26 MySQL Community Server (GPL)
Copyright (c) 2000, 2019, 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>
第七步：增加一个新用户用于navicat远程连接
mysql> GRANT ALL PRIVILEGES ON *.* TO 'zhoushuai'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION ;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
mysql>
第八步：配置默认编码为utf8，进入/etc/my.cnf配置文件，在[mysqld]下添加编码配置，如下所示：
character_set_server=utf8
init_connect='SET NAMES utf8'
第九步：安装完成
第十步：阿里云放开3306端口
网友评论