root@centos64 mysql]# /usr/bin/mysqld_safe --skip-grant-tables&
2. 再启一个终端执行下面的一系列命令：
[root@centos64 proc]# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.13 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> UPDATE user SET password=password('admin') WHERE user='root';
ERROR 1046 (3D000): No database selected
mysql> show databases ;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
4 rows in set (0.06 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('admin') WHERE user='root';
Query OK, 4 rows affected (0.04 sec)
Rows matched: 4 Changed: 4 Warnings: 0
mysql> flush privileges; 也可以不用。
mysql> exit
Bye注意，就是有可能，user表中根本就没有root这个用户。
如果没有此用户，用：
mysql> insert into mysql.user(Host,User,Password,ssl_cipher,x509_issuer,x509_subject) values("localhost","root",password("admin"),"","","");
Query OK, 1 row affected (0.10 sec)3.授权。 给所有的权限
mysql> grant all privileges on *.* to 'root'@'localhost' identified by 'admin' ; Query OK, 0 rows affected (0.06 sec) mysql> flush privileges;
再以正常的方式启动即可。