之前在各大论坛上看到有很多相关介绍，但是总觉得自己安装的时候有些问题，所以这一篇借鉴
博客园-大大的橙子，但是，他的文章中安装过程中有有点问题，所以在其基础上进行了修修补补，所以目前本人经过多次裸机安装，亲测正常。

卸载系统自带的Mariadb

[root@aliyun ~]# rpm -qa|grep mariadb
mariadb-libs-5.5.44-2.el7.centos.x86_64
[root@aliyun ~]# rpm -e --nodeps mariadb-libs-5.5.44-2.el7.centos.x86_64

删除etc目录下的my.cnf文件

[root@aliyun ~]# rm /etc/my.cnf
rm: cannot remove ?etc/my.cnf? No such file or directory

检查mysql是否存在

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

安装必要软件

[root@aliyun ~]# yum install -y libaio

检查mysql组和用户是否存在，如无创建

[root@aliyun ~]# cat /etc/group | grep mysql 
[root@aliyun ~]#  cat /etc/passwd | grep mysql

创建mysql用户组

[root@aliyun ~]# groupadd mysql

创建一个用户名为mysql的用户并加入mysql用户组

[root@aliyun ~]# useradd -g mysql mysql

制定password 为111111

[root@aliyun ~]# passwd mysql
Changing password for user mysql.
New password: 
BAD PASSWORD: The password is a palindrome
Retype new password: 
passwd: all authentication tokens updated successfully.

由于我的/usr/local空间不足，所以我安装到/var

[root@aliyun var]# tar -zxvf mysql-5.7.18-linux-glibc2.5-x86_64.tar.gz 
[root@aliyun var]# mv mysql-5.7.18-linux-glibc2.5-x86_64/ mysql57

更改所属的组和用户

[root@aliyun var]# chown -R mysql mysql57/
[root@aliyun var]# chgrp -R mysql mysql57/
[root@aliyun var]# cd mysql57/

[root@aliyun mysql57]# mkdir data

[root@aliyun mysql57]# chown -R mysql:mysql data

配置my.cnf

[mysql]
# 设置mysql客户端默认字符集
default-character-set=utf8 
[mysqld]
skip-name-resolve
#设置3306端口
port = 3306 
# 设置mysql的安装目录
basedir=/var/mysql57
# 设置mysql数据库的数据的存放目录
datadir=/var/mysql57/data
# 允许最大连接数
max_connections=200
# 服务端使用的字符集默认为8比特编码的latin1字符集
character-set-server=utf8
# 创建新表时将使用的默认存储引擎
default-storage-engine=INNODB 
lower_case_table_names=1
max_allowed_packet=16M

开始初始化安装，注意里面的数据库密码，请暂时先保存下来，是初始化密码，登陆后再修改

shell> bin/mysqld --initialize --user=mysql --basedir=/var/mysql57/ --datadir=/var/mysql57/data/
2018-01-31T14:15:21.160016Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-01-31T14:15:25.102080Z 0 [Warning] InnoDB: New log files created, LSN=45790
2018-01-31T14:15:25.537811Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2018-01-31T14:15:25.646880Z 0 [Warning] Failed to setup SSL
2018-01-31T14:15:25.716100Z 0 [Warning] SSL error: SSL context is not usable without certificate and private key
2018-01-31T18:14:25.716295Z 1 [Warning] A temporary password is generated for root@localhost: rq/Dldw^lkdfd

[root@aliyun mysql57]# cp ./support-files/mysql.server /etc/init.d/mysqld
[root@aliyun mysql57]# chown 777 /etc/my.cnf 
[root@aliyun mysql57]# chmod +x /etc/init.d/mysqld

[root@aliyun mysql57]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL. SUCCESS! 

设置开机启动

[root@aliyun mysql57]# chkconfig --level 35 mysqld on
[root@aliyun mysql57]# chkconfig --list mysqld

[root@aliyun mysql57]# chmod +x /etc/rc.d/init.d/mysqld
[root@aliyun mysql57]# chkconfig --add mysqld
[root@aliyun mysql57]# chkconfig --list mysqld
[root@aliyun mysql57]# service mysqld status
 SUCCESS! MySQL running (4475)

设置/etc/profile环境 在尾部添加

export PATH=$PATH:/var/mysql57/bin

执行source 使配置文件生效

[root@aliyun mysql57]# source /etc/profile

使用初始密码，进行连接数据库

[root@aliyun bin]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.18

Copyright (c) 2000, 2017, 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.
#修改密码为 111111
mysql> set PASSWORD = PASSWORD('111111');
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

#添加远程访问权限
mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

mysql> update user set host='%' where user='root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select host,user from user;
+-----------+-----------+
| host      | user      |
+-----------+-----------+
| %         | root      |
| localhost | mysql.sys |
+-----------+-----------+
rows in set (0.00 sec)


create user 'xxx'@'%' identified by '123';  这里 @‘%’ 表示在任何主机都可以登录

重启生效

[root@aliyun bin]# /etc/init.d/mysqld restart 
Shutting down MySQL.. SUCCESS! 
Starting MySQL. SUCCESS! 

设置任何目录下都可以使用mysql命令

ln -s /var/mysql57/bin/mysql   /usr/bin/mysql