MySQL忘记root密码怎么办？

root@centos64 mysql]# /usr/bin/mysqld_safe --skip-grant-tables&

2.  再启一个终端：

[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)

2.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。