云服务器下Mysql安装和配置

Mysql完全卸载

删除Mysql：

yum remove mysql mysql-server mysql-libs mysql-server;
find / -name mysql 将找到的相关东西delete掉(比如rm -rf /var/lib/mysql)；
rpm -qa|grep mysql(查询出来的东东yum remove掉)
rm /etc/my.cnf

然后查看是否还有mysql软件：
rpm -qa|grep mysql

如果存在的话，继续删除即可。

安装Mysql

#yum install mysql
#yum install mysql-server
#yum install mysql-devel

安装mysql和mysql-devel都成功，但是安装mysql-server失败，如下：

[root@yl-web yl]# yum install mysql-server
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.sina.cn
 * extras: mirrors.sina.cn
 * updates: mirrors.sina.cn
No package mysql-server available.
Error: Nothing to do

查资料发现是CentOS 7 版本将MySQL数据库软件从默认的程序列表中移除，用mariadb代替了。
解决办法如下：

# wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
# rpm -ivh mysql-community-release-el7-5.noarch.rpm
# yum install mysql-community-server

安装成功后重启mysql服务。
# service mysqld restart
初次安装mysql，root账户没有密码。如果登陆不成功的话，设置vi /etc/my.cnf，然后在最后添加一行skip-grant-tables即可。

[root@yl-web yl]# mysql -u root 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.6.26 MySQL Community Server (GPL)

Copyright (c) 2000, 2015, 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> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
rows in set (0.01 sec)

mysql>

设置密码:

mysql> set password for 'root'@'localhost' =password('password');
Query OK, 0 rows affected (0.00 sec)

mysql>

把在所有数据库的所有表的所有权限赋值给位于所有IP地址的root用户。
mysql> grant all privileges on *.* to root@'%'identified by 'password';