先停了mysql，然后找到my.cnf文件，

在[mysqld]加skip-grant-tables

保存，退出

然后

vincent-guo:bin vincent$ mysql -u -p

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 1

Server version: 5.6.10 MySQL Community Server (GPL)

Copyright (c) 2000, 2013, 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.

mysql> show databaes;

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'databaes' at line 1

mysql> show databases;

+--------------------+

| Database |

+--------------------+

| information_schema |

| alldata |

| emailsys |

| microlife |

| mysql |

| performance_schema |

| test |

+--------------------+

7 rows in set (0.07 sec)

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

mysql> update user set password=password('P@ssw0rd') where use = 'root';

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'use = 'root'' at line 1

mysql> update user set password=password('P@ssw0rd') where user = 'root';

Query OK, 3 rows affected (0.04 sec)

Rows matched: 4 Changed: 3 Warnings: 0

mysql> select user from user;

+------+

| user |

+------+

| root |

| root |

| root |

| |

| |

| root |

+------+

6 rows in set (0.04 sec)

mysql> delete from user where user='';//删除用户名为空的用户

Query OK, 2 rows affected (0.04 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql>