mysql ubuntu 开启3306端口，设置远程访问

远程登陆数据库的时候出现了下面出错信息 :
ERROR 2003 ( HY000 ) : Can 't connect to MySQL server on ’ xxx.xxx.xxx.xxx ’

1. 没有授予相应的权限:

例如，你想root使用123456从任何主机连接到mysql服务器

mysql>GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH
GRANT OPTION;
mysql>flush privileges;

如果你想允许用户jack从ip为106.13.53.13的主机连接到mysql服务器，并使用123456作为密码

mysql>GRANT ALL PRIVILEGES ON *.* TO 'jack'@’106.13.53.13’ IDENTIFIED BY '123456' WITH GRANT OPTION;
mysql>flush privileges;

2. 修改mysql数据库中的user表使相应的用户能从某一主机登陆

mysql -u root –p
mysql>use mysql;
mysql>update user set host = '%' where user = 'root';
mysql>select host, user from user;

3. 防火墙禁止了3306端口，以ufw为例

sudo apt-get install ufw
sudo ufw disable
sudo ufw status

4. 修改MySQL的配置文件
   (我这边是在这个目录，每个人目录不同) /etc/mysql/mysql.conf.d/mysqld.cnf，
   因为默认3306端口只允许本地访问的，注释掉这行

# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.

#bind-address = 127.0.0.1

然后重启Mysql，service mysql restart