Centos7安装mysql5.7

解压下载的tar包到 /home/mysql/下，得到rpm包，命令如下：

	tar -xf mysql-5.7.19-1.el7.x86_64.rpm-bundle.tar -C /home/mysql/

#查询并卸载系统自带的Mariadb 命令如下：

rpm -qa | grep mariadb--------------------查询带有mariadb的文件
rpm -e --nodeps 上一步列出的文件名------强制卸载mariadb

#查询并卸载老版本的MySQL：

rpm -qa | grep mysql
rpm -e --nodeps 文件名

#安装依赖

yum install   net-tools -y
yum install   perl -y  

#安装mysql（下面四条命令顺序不能变）

rpm -ivh mysql-community-common-5.7.14-1.el7.x86_64.rpm 
rpm -ivh mysql-community-libs-5.7.14-1.el7.x86_64.rpm 
rpm -ivh mysql-community-client-5.7.14-1.el7.x86_64.rpm 
rpm -ivh mysql-community-server-5.7.14-1.el7.x86_64.rpm 

#启动mysql服务

systemctl start mysqld

#MySQL为root用户生成的随机密码通过mysqld.log文件可以查找到

grep 'temporary password' /var/log/mysqld.log

#修改密码

set global validate_password_policy=0;
set global validate_password_length=4;
set password for root@localhost=password("root");
GRANT ALL PRIVILEGES  ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;
FLUSH PRIVILEGES;