centos 安装mysql，更改初始密码

安装环境：CentOS7 64位 MINI版，安装MySQL5.7

1、配置YUM源

在MySQL官网中下载YUM源rpm安装包：http://dev.mysql.com/downloads/repo/yum/ 

# 下载mysql源安装包
shell> wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
# 安装mysql源
shell> yum localinstall mysql57-community-release-el7-8.noarch.rpm

检查mysql源是否安装成功

shell> yum repolist enabled | grep "mysql.*-community.*"

 
看到上图所示表示安装成功。 
可以修改vim /etc/yum.repos.d/mysql-community.repo源，改变默认安装的mysql版本。比如要安装5.6版本，将5.7源的enabled=1改成enabled=0。然后再将5.6源的enabled=0改成enabled=1即可。改完之后的效果如下所示： 

2、安装MySQL

shell> yum install mysql-community-server

3、启动MySQL服务

shell> sudo systemctl start mysqld

查看MySQL的启动状态

shell> sudo systemctl status mysqld
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; disabled; vendor preset: disabled)
   Active: active (running) since 五 2016-06-24 04:37:37 CST; 35min ago
 Main PID: 2888 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─2888 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

6月 24 04:37:36 localhost.localdomain systemd[1]: Starting MySQL Server...
6月 24 04:37:37 localhost.localdomain systemd[1]: Started MySQL Server.

4、开机启动

sudo systemctl restart mysqld

5、登录mysql（第一次登录，要输入密码直接回车）：

sudo mysql -uroot -p

6、更改密码：

set password for 'root'@'localhost'=password('你的新密码');

7、退出登录mysql：

exit

8、重启mysql：

sudo systemctl restart mysqld

9、然后你再登录mysql

sudo mysql -uroot -p

发现这时就得输入刚才的密码才行了