1、查看是否安裝歷史版本

# 查看
rpm -qa|grep mysql
rpm -qa|grep mariadb
# 卸載
yum -y remove  #mysql安裝包名稱
yum -y remove  #mariadb安裝包名稱

2、下載安裝

[root@localhost ~]# wget http://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm
[root@localhost ~]# rpm -ivh mysql57-community-release-el7-8.noarch.rpm
[root@localhost ~]# yum install -y mysql mysql-server
[root@localhost ~]# mysql -V   //查看當(dāng)前安裝mysql版本
mysql  Ver 14.14 Distrib 5.7.27, for Linux (x86_64) using  EditLine wrapper

3、修改密碼

[root@localhost ~]# systemctl start mysqld   //啟動mysql服務(wù)
[root@localhost ~]# grep "password" /var/log/mysqld.log  //通過log查看初始密碼
2021-08-05T16:17:00.010786Z 1 [Note] A temporary password is generated for root@localhost: i0d?ur_#rr+O0    //i0d?ur_#rr+O0此為mysql初始密碼
[root@localhost ~]# mysql -u root -p  
Enter password:                         //輸入初始密碼i8d?ur_#rr+O
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.27
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 'Password';   //重置mysql密碼為：Password
Query OK, 0 rows affected (0.00 sec)

mysql> update mysql.user set host='%' where host='localhost';  //root用戶可使用任意IP登錄數(shù)據(jù)庫
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3  Changed: 3  Warnings: 0

mysql> flush privileges;   //刷新權(quán)限