ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'mysql'

前两天装了mysql免安装版，但是没有设账户和密码，今天新建数据库时总不成功，上网查了一下，是因为没有设密码的原因。于是去设密码，设密码要使用 “mysql” 这个数据库，但是会报错。ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'mysql'

后来发现解决办法，把my.ini中加入skip-grant-tables。

[mysqld]
skip-grant-tables

# Remove leading # and set to the amount of RAM for the most important data

就像这样，然后在去重启mysql，我是在服务中重启的。

接着打开mysql

<pre name="code" class="html"><pre name="code" class="html">Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.25 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.

这时，便可以 use mysql了。

mysql> use mysql
Database changed
mysql>

然后修改密码

mysql> update user set password=password('12345') where user='root';
Query OK, 3 rows affected (0.05 sec)
Rows matched: 3  Changed: 3  Warnings: 0

退出，将my.ini改过来，就可以了