首先让我提一下，我已经看了很多建议的问题，但没有找到相关的答案。这就是我正在做的。
我连接到Amazon EC2实例。我可以用这个命令登录MySQL根目录:
mysql -u root -p
然后我用host %创建了一个新的用户帐单
CREATE USER 'bill'@'%' IDENTIFIED BY 'passpass';
授予用户bill的所有权限:
grant all privileges on *.* to 'bill'@'%' with grant option;
然后我退出root用户，尝试用bill登录:
mysql -u bill -p
输入正确的密码并得到以下错误:
错误1045(28000):用户“账单”@“localhost”(使用密码:YES)的访问被拒绝
当前回答
好吧，我不确定，但可能是mysql安装目录中的my.cnf文件是罪魁祸首。 注释掉这一行，问题就可以解决了。
bind-address = 127.0.0.1
其他回答
对我来说，这个问题是由MySQL 5.7.2的一个新特性引起的:如果用户的插件字段为空，用户条目将被忽略。
设置为mysql_native_password以重新启用它们:
UPDATE user SET plugin='mysql_native_password' WHERE user='foo';
FLUSH PRIVILEGES;
请参阅MySQL 5.7.2的发布说明，在«Authentication notes»下。
由于某些原因(可能是因为我在4.1之前的密码散列被删除了)，mysql_upgrade脚本没有设置默认的插件值。
我是通过注意/var/log/mysql/error.log中的以下警告消息发现的:
[警告]用户条目“foo”@“%”的插件值为空。该用户将被忽略，任何人都不能再使用该用户登录。
我把这个答案贴在这里，也许是为了让别人不用像我一样花那么多荒谬的时间来研究这个问题。
Try:
~$ mysql -u root -p
Enter Password:
mysql> grant all privileges on *.* to bill@localhost identified by 'pass' with grant option;
如果您忘记密码或想修改密码。你可以遵循以下步骤:
1 :stop your mysql [root@maomao ~]# service mysqld stop Stopping MySQL: [ OK ] 2 :use “--skip-grant-tables” to restart mysql [root@mcy400 ~]# mysqld_safe --skip-grant-tables [root@cy400 ~]# Starting mysqld daemon with databases from /var/lib/mysql 3 : open a new window and input mysql -u root [root@cy400 ~]# mysql -u root Welcome to the MySQL monitor. Commands end with ; or \g. 4 : change the user database mysql> use mysql Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed 5 : modify your password your new password should be input in "（）" mysql> update user set password=password('root123') where user='root'; Query OK, 3 rows affected (0.00 sec) Rows matched: 3 Changed: 3 Warnings: 0 6 : flush mysql> flush privileges; 7: quit mysql> quit Bye 8: restart mysql [root@cy400 ~]# service mysqld restart; Stopping MySQL: [ OK ] Starting MySQL: [ OK ]
宾果!你可以用用户名和新密码连接你的数据库:
[root@cy400 ~]# mysql -u root -p <br>
Enter password: admin123 <br>
Welcome to the MySQL monitor. Commands end with ; or \g. <br>
Your MySQL connection id is 2 <br>
Server version: 5.0.77 Source distribution <br>
Type 'help;' or '\h' for help. Type '\c' to clear the buffer. <br>
mysql> quit <br>
Bye
如果您使用旧版本的MySQL UI(如SQLYoug)，生成的密码带有错误的散列，也会出现这个问题。
用SQL脚本创建用户可以解决这个问题。
I discovered yet another case that appears on the surface to be an edge case; I can export to the file system, via SELECT INTO .. OUTFILE as root, but not as regular user. While this may be a matter of permissions, I've looked at that, and see nothing especially obvious. All I can say is that executing the query as a regular user who has all permissions on the data base in question returns the access denied error that led me to this topic. When I found the transcript of a successful use of SELECT INTO … OUTFILE in an old project, I noticed that I was logged in as root. Sure enough, when I logged in as root, the query ran as expected.
