CentOS7 安装MYSQL5.7 [详细过程]

YUM 安装

1.从mysql官网获取 yum 仓库

[root@stone tmp]# wget 'https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm'

2.安装yum repo

[root@stone tmp]# rpm -ivh mysql57-community-release-el7-11.noarch.rpm
警告：mysql57-community-release-el7-11.noarch.rpm: 头V3 DSA/SHA1 Signature, 密钥 ID 5072e1f5: NOKEY
准备中...                          ################################# [100%]
正在升级/安装...
   1:mysql57-community-release-el7-11 ################################# [100%]

3.安装mysql

[root@stone tmp]# yum install -y mysql-community-server

4.如果安装过程中出现如下错误

源 "MySQL 5.7 Community Server" 的 GPG 密钥已安装，但是不适用于此软件包。请检查源的公钥 URL 是否配置正确。

使用如下命令
[root@stone rpm-gpg]# rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022

5.启动mysql

[root@stone rpm-gpg]#  systemctl start  mysqld.service

6.查看运行状态

[root@stone rpm-gpg]#  systemctl status  mysqld.service   
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since 日 2022-05-01 00:00:35 CST; 30s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 2067 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 2018 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 2070 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─2070 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

5月 01 00:00:32 stone systemd[1]: Starting MySQL Server...
5月 01 00:00:35 stone systemd[1]: Started MySQL Server.

7.登录数据库

第一次启动的密码在日志中查找
[root@stone rpm-gpg]# cat /var/log/mysqld.log | grep password
2022-04-30T16:00:33.315107Z 1 [Note] A temporary password is generated for root@localhost: ZpiMyUag.4wl
[root@stone rpm-gpg]# 

8.登录后修改密码，如果要是设置复杂密码可以直接使用如下命令 直接设置

mysql> SET PASSWORD = PASSWORD('your new password');
mysql> flush privileges;

9. 如果要设置简单密码 则需要先使用如下命令 设置密码策略

mysql> set global validate_password_policy=0;#设置密码检查策略为0
mysql> set global validate_password_length=1;#设置密码的长度为1

10.授权用户登录权限

mysql> grant all privileges on *.* to root@"%" identified by "new passwd";
mysql> flush privileges;

11.如果忘记密码

1. 暂停服务
systemctl stop mysql.service
2. 修改/etc/my.cnf 
添加 skip-grant-tables 配置项目
3. 重启mysql服务
4. mysql -uroot -p 进入数据库
5. update user set password = password ( 'new-password' ) where user = 'root';
6. flush privileges;