1.下载mysql-5.7.27-linux-glibc2.12-x86_64.tar.gz
https://dev.mysql.com/downloads/mysql/5.7.html#downloads
或者命令下载：wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.27-linux-glibc2.12-x86_64.tar.gz
2.安装前检查是否安装了mysql
rpm -qa | grep mysql
3.如过出现类似如下信息
mysql-libs-5.1.52-1.el6_0.1.x86_64
4.卸载
rpm -e mysql-libs-5.1.52-1.el6_0.1.x86_64 // 普通删除模式
rpm -e --nodeps mysql-libs-5.1.52-1.el6_0.1.x86_64 // 强力删除模式，如果使用上面命令删除时，提示有依赖的其它文件，则用该命令可以对其进行强力删除
5.检查否存在 mariadb 数据库，如有，卸载同上
6.将下载好的mysql上传到指定目录
/opt/mysql
7.解压
tar -zxvf mysql-5.7.27-linux-glibc2.12-x86_64.tar.gz
8.重命名
mv mysql-5.7.27-linux-glibc2.12-x86_64.tar.gz mysql-5.7.27
9.检查mysql组和用户是否存在，如无创建
cat /etc/group | grep mysql
#类似
mysql:x:490:
cat /etc/passwd | grep mysql
#类似
mysql:x:496:490::/home/mysql:/bin/bash
10.以上为存在的情况，如无，执行添加命令：
groupadd mysql
useradd -r -g mysql mysql
#useradd -r参数表示mysql用户是系统用户，不可用于登录系统
11.创建data目录
cd mysql-5.7.27
mkdir data
12.将/opt/mysql/mysql-5.7.25的所有者及所属组改为mysql
chown -R mysql.mysql /opt/mysql/mysql-5.7.27
13.在/opt/mysql/mysql-5.7.25/support-files目录下创建my_default.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.
[mysqld]
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
basedir = /opt/mysql/mysql-5.7.27
datadir = /opt/mysql/mysql-5.7.27/data
port = 3306
socket = /tmp/mysql.sock
character-set-server=utf8
log-error = /opt/mysql/mysql-5.7.27/data/mysqld.log
pid-file = /opt/mysql/mysql-5.7.27/data/mysqld.pid
14.拷贝，如果提示是否覆盖，y
cp support-files/my_default.cnf /etc/my.cnf
15初始化 mysqld
./bin/mysqld --initialize --user=mysql --basedir=/opt/mysql/mysql-5.7.27/ --datadir=/opt/mysql/mysql-5.7.27/data/
16.若报错 mysqld: [ERROR] Found option without preceding group in config file /etc/my.cnf at line 1!
检查/etc/my.cnf文件是否复制的时候第一行没有复制完全
17.初始化完成之后，查看日志
/opt/mysql/mysql-5.7.27/data/mysqld.log
18.最后一行的临时密码
A temporary password is generated for root@localhost: 2I8_DZ/WpaE%
19.把启动脚本放到开机初始化目录
cp support-files/mysql.server /etc/init.d/mysql
20.启动mysql服务
service mysql start
21.登录mysql，密码为上述初始密码
./bin/mysql -u root -p
22.修改密码
mysql> set password=password('123456');
mysql> grant all privileges on *.* to root@'%' identified by '123456';
mysql> flush privileges;
23.添加远程访问权限
mysql> use mysql;
mysql> update user set host='%' where user = 'root';
mysql> flush privileges;
24.重启mysql生效
service mysql stop
service mysql start
或
service mysql restart
