CentOS8安装Mysql5.7

检查是否安装mysql

[root@iZ2ze8crquorxf6c7l0eluZ ~]# rpm -qa |grep mysql
[root@iZ2ze8crquorxf6c7l0eluZ ~]# 

没有任何返回代表没有安装mysql

安装mysql

1、安装wget（wget是Linux中的一个下载文件的工具）

[root@iZ2ze8crquorxf6c7l0eluZ ~]# yum install wget
Last metadata expiration check: 1:30:08 ago on Mon 17 Aug 2020 11:35:44 AM CST.
Package wget-1.19.5-8.el8_1.1.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!

这个是已经安装成功的提示
2、 下载mysql的rpm

[root@iZ2ze8crquorxf6c7l0eluZ ~]# wget http://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm
--2020-08-17 13:21:05--  http://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm
Resolving dev.mysql.com (dev.mysql.com)... 137.254.60.11
Connecting to dev.mysql.com (dev.mysql.com)|137.254.60.11|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm [following]
--2020-08-17 13:21:06--  https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm
Connecting to dev.mysql.com (dev.mysql.com)|137.254.60.11|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm [following]
--2020-08-17 13:21:11--  https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm
Resolving repo.mysql.com (repo.mysql.com)... 23.211.97.88
Connecting to repo.mysql.com (repo.mysql.com)|23.211.97.88|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 26024 (25K) [application/x-redhat-package-manager]
Saving to: ‘mysql80-community-release-el7-3.noarch.rpm’

mysql80-community-release-el7-3.noarc 100%[======================================================================>]  25.41K  --.-KB/s    in 0.1s    

2020-08-17 13:21:11 (229 KB/s) - ‘mysql80-community-release-el7-3.noarch.rpm’ saved [26024/26024]

3、安装mysql的rpm

[root@iZ2ze8crquorxf6c7l0eluZ ~]# rpm -ivh mysql80-community-release-el7-3.noarch.rpm
warning: mysql80-community-release-el7-3.noarch.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Verifying...                          ################################# [100%]
Preparing...                          ################################# [100%]
Updating / installing...
   1:mysql80-community-release-el7-3  ################################# [100%]

/etc/yum.repos.d/目录下生成两个文件
mysql-community.repo和mysql-community-source.repo
4、修改repo文件

[root@iZ2ze8crquorxf6c7l0eluZ ~]# cd /etc/yum.repos.d/
[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# vim mysql-community.repo

将5.7的enable改为1，8.0的enable改为0

i进入修改模式-》修改-》esc退出修改模式-》:wq保存并退出
5、安装Mysql

[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# yum -y install mysql-community-server

如果报错Error: Unable to find a match: mysql-community-server
先执行下面语句再安装

yum module disable mysql

6、查看Mysql版本

[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# mysql --version
mysql  Ver 14.14 Distrib 5.7.31, for Linux (x86_64) using  EditLine wrapper

7、启动Mysql并查看Mysql状态

[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: inactive (dead)
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# systemctl start mysqld.service
[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2020-08-17 14:06:31 CST; 5s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 30074 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 30018 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 30077 (mysqld)
    Tasks: 27 (limit: 11516)
   Memory: 342.9M
   CGroup: /system.slice/mysqld.service
           └─30077 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

Aug 17 14:05:56 iZ2ze8crquorxf6c7l0eluZ systemd[1]: Starting MySQL Server...

8、查看mysql临时密码

[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# grep 'temporary password' /var/log/mysqld.log
2020-08-17T06:06:28.781067Z 1 [Note] A temporary password is generated for root@localhost: lF%_XqVtO5XW

9、登录mysql

[root@iZ2ze8crquorxf6c7l0eluZ yum.repos.d]# mysql -uroot -plF%_XqVtO5XW

9、修改mysql登录密码

set global validate_password_policy=LOW;
set global validate_password_length=4;
SET PASSWORD FOR 'root'@'localhost' = PASSWORD('输入新密码');

修改Mysql8.0密码不满足当前策略要求解决方 随便找的
先修改密码策略然后设置密码，或者设置一个很复杂的密码也行
10、添加远程访问用户

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '密码' WITH GRANT OPTION;
flush privileges; 

创建了一个可以在任意IP访问的用户