解决 Error Code: 1044. Access denied for user 'root'@'%' to database

今天在测试集群用的 mysql 上，遇到个权限的问题：
SQLException : SQL state: 42000 com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Access denied for user 'root'@'%' to database 'ranger' ErrorCode: 1044

我是以 root 用户登录 mysql 的，怎么还会遇到这问题呢，有点猫腻，我查看了下 mysql 下 user 表的各用户的权限信息

mysql> SELECT host,user,password,Grant_priv,Super_priv FROM mysql.user;
+--------------+---------+-------------------------------------------+------------+------------+
| host         | user    | password                                  | Grant_priv | Super_priv |
+--------------+---------+-------------------------------------------+------------+------------+
| localhost    | root    | *84BB87F6BF7F61703B24CE1C9AA9C0E3F2286900 | N          | N          |
| localhost    | root    | 0                                         | Y          | Y          |
| %            | root    | *FED29C14B2E900D70B11B1F1B370F953BA51A6A0 | N          | Y          |
| 127.0.0.1    | root    | *FED29C14B2E900D70B11B1F1B370F953BA51A6A0 | Y          | Y          |
| %            | root    | *84BB87F6BF7F61703B24CE1C9AA9C0E3F2286900 | N          | Y          |
+--------------+---------+-------------------------------------------+------------+------------+

可以看到授权的权限没有打开： Grant_priv is set to N for root@%. 修复下

UPDATE mysql.user SET Grant_priv='Y', Super_priv='Y' WHERE User='root';
FLUSH PRIVILEGES;

重新登录下，就 ok 了。