Navicat链接mysql数据库报错：1045 - Access denied for user 'root'@'localhost' (using password: YES)

Navicat链接mysql数据库报错：1045 - Access denied for user 'root'@'localhost' (using password: YES)。

这是数据库权限的问题，workbench等也会一样报错

问题所在：未给root用户分配全部权限，本地客户端无权限登陆root用户。

以root用户登陆mysql，运行show grants for 'user'@'IP';

show grants for 'root'@'192.168.170.136';
ERROR 1141 (42000): There is no such grant defined for user 'root' on host '192.168.170.136'

show grants for 'root'@'localhost';
+----------------------------------------------------------------------------------------------------------------------------------------+
| Grants for root@localhost                                                                                                              |
+----------------------------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY PASSWORD '*81F5E21E35407D884A6CD4A731AEBFB6AF209E1B' WITH GRANT OPTION |
+----------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

经过上述两个查询语句的对比，说明root用户只给了本地服务器的访问权限，而没有给192.168.170.136客户端的访问权限。

也能够经过查询mysql的user表来查看用户权限：

select user,host from mysql.user;

+-------+---------------+
| user  | host          |
+-------+---------------+
| root  | localhost     | 
+-------+---------------+
1 rows in set (0.00 sec)

说明root用户只对localhost授予了访问权限。

解决方法：进行root用户的远程访问受权，能够受权到指定的客户端IP，也能够受权为全部IP均可访问（host值为%）：

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;
Query OK, 0 rows affected (0.00 sec)

flush privileges;
Query OK, 0 rows affected (0.00 sec)

select user,host,password from mysql.user;
+-------+---------------+-------------------------------------------+
| user  | host          | password                                  |
+-------+---------------+-------------------------------------------+
| root  | localhost     | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B | 
| root  | %             | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B | 
+-------+---------------+-------------------------------------------+
2 rows in set (0.00 sec)

这样就ok了。