[root@localhost ~]# rpm -qa|grep mariadb 　　// 查询出来已安装的mariadb

[root@localhost ~]# rpm -e --nodeps 文件名 　　// 卸载mariadb，文件名为上述命令查询出来的文件
[root@localhost ~]# rm /etc/my.cnf　　　　　　//删除配置文件

[root@localhost ~]# groupadd mysql    //创建mysql用户组

[root@localhost ~]# useradd -g mysql mysql      //创建mysql用户，并添加到mysql用户组

[root@localhost ~]# tar -zvxf mysql-5.7.-linux-glibc2.-x86_64.tar.gz

[root@localhost ~]# mv 解压出来的文件夹名 mysql

[root@localhost ~]# mv mysql /usr/local/

[root@localhost support-files]# vim /etc/my.cnf

#通过vim编辑器编辑my.cnf代码如下：

[mysqld]
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

basedir = /usr/local/mysql
datadir = /usr/local/mysql/data
port = 3306
socket = /tmp/mysql.sock
character-set-server=utf8

log-error = /usr/local/mysql/data/mysqld.log
pid-file = /usr/local/mysql/data/mysqld.pid

[root@localhost ~]# cd /usr/local/mysql/bin/

[root@localhost bin]# ./mysqld --initialize --user=mysql --basedir=/usr/local/mysql/ --datadir=/usr/local/mysql/data/

[root@localhost bin]# cat /usr/local/mysql/data/mysqld.log 

--05T07::.263392Z  [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).

--05T07::.263457Z  [Warning] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict mode. They will be merged with strict mode in a future release.

--05T07::.263462Z  [Warning] 'NO_AUTO_CREATE_USER' sql mode was not set.

--05T07::.961752Z  [Warning] InnoDB: New log files created, LSN=

--05T07::.039265Z  [Warning] InnoDB: Creating foreign key constraint system tables.

--05T07::.095290Z  [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: b858de41--11e9-84f3-00505681edfc.

--05T07::.096413Z  [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.

--05T07::.096953Z  [Note] A temporary password is generated for root@localhost: kXJh+_RMu52K

[root@localhost ~]# cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql

[root@localhost ~]# service mysql start

Starting MySQL. SUCCESS! 

[root@localhost ~]# cd /usr/local/mysql/bin/

[root@localhost bin]# ./mysql -uroot -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is

Server version: 5.7.

Copyright (c) , , 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> 

mysql> set password=password('root');

Query OK,  rows affected,  warning (0.00 sec)

mysql> grant all privileges on *.* to root@'%' identified by '';

Query OK,  rows affected,  warning (0.01 sec)

mysql> flush privileges;

Query OK,  rows affected (0.00 sec)

mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '' WITH GRANT OPTION;

Query OK,  rows affected,  warning (0.00 sec)

[root@localhost bin]# service mysql restart

Shutting down MySQL.. SUCCESS!

Starting MySQL. SUCCESS!