起因：

刚刚搭建好的mysql数据库，做基础优化时，不小心把所有用户都删除了，并且退出了。没办法，只好跳过授权表登录，新建root用户。

过程如下：

一、停掉mysql，跳过授权登录

[root@explnk-zabbix zabbix-2.2.9]# /etc/init.d/mysqld stop

Shutting down MySQL... SUCCESS!

[root@explnk-zabbix zabbix-2.2.9]# mysqld_safe --skip-grant-table &

[1] 30178

[root@explnk-zabbix zabbix-2.2.9]# 160418 10:49:54 mysqld_safe Logging to '/application/mysql/data/explnk-zabbix.err'.

160418 10:49:54 mysqld_safe Starting mysqld daemon with databases from /application/mysql/data

[root@explnk-zabbix zabbix-2.2.9]# mysql

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

Your MySQL connection id is 1

Server version: 5.5.32 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>

二、创建拥有root权限的用户

2.1 错误例子：

这里最开始遇到个坑，使用insert into创建的用户没有任何权限，登录之后无法进行操作，语句如下：

INSERT INTO user (Host,User,Password) VALUES('localhost','root',PASSWORD('biscuit'));

*************************** 2. row ***************************

Host: localhost

User: root

Password: *7495041D24E489A0096DCFA036B166446FDDD992

Select_priv: N

Insert_priv: N

Update_priv: N

Delete_priv: N

Create_priv: N

Drop_priv: N

Reload_priv: N

Shutdown_priv: N

Process_priv: N

File_priv: N

Grant_priv: N

References_priv: N

Index_priv: N

Alter_priv: N

Show_db_priv: N

Super_priv: N

Create_tmp_table_priv: N

Lock_tables_priv: N

Execute_priv: N

Repl_slave_priv: N

Repl_client_priv: N

Create_view_priv: N

Show_view_priv: N

Create_routine_priv: N

Alter_routine_priv: N

Create_user_priv: N

Event_priv: N

Trigger_priv: N

Create_tablespace_priv: N

ssl_type:

ssl_cipher:

x509_issuer:

x509_subject:

max_questions: 0

max_updates: 0

max_connections: 0

max_user_connections: 0

plugin:

authentication_string: NULL

2.2 正确方法1：

mysql> use mysql

Database changed

mysql> insert into user (Select_priv,           Insert_priv,           Update_priv,           Delete_priv,           Create_priv,             Drop_priv,           Reload_priv,         Shutdown_priv,          Process_priv,             File_priv,            Grant_priv,       References_priv,            Index_priv,            Alter_priv,          Show_db_priv,            Super_priv, Create_tmp_table_priv,      Lock_tables_priv,          Execute_priv,       Repl_slave_priv,      Repl_client_priv,      Create_view_priv,        Show_view_priv,   Create_routine_priv,    Alter_routine_priv,      Create_user_priv,            Event_priv,          Trigger_priv,Create_tablespace_priv,User,Password) values ( 'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','gl','gl');

Query OK, 1 row affected, 3 warnings (0.06 sec)

mysql> update user set password=PASSWORD('explink') where user='gl';

Query OK, 1 row affected (0.08 sec)

Rows matched: 1  Changed: 1  Warnings: 0

2.3 正确方法2：

跳过授权表登录后是无法使用grant建立用户的，报错如下：

mysql> grant all privileges on *.* to liang@'localhost' identified by '123456' with grant option;

ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

解决办法：

只要刷新一下用户权限即可

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> grant all privileges on *.* to liang@'localhost' identified by '123456' with grant option;

Query OK, 0 rows affected (0.00 sec)

三、退出登录并重新启动mysql

[root@explnk-zabbix zabbix-2.2.9]# /etc/init.d/mysqld stop

[root@explnk-zabbix zabbix-2.2.9]# /etc/init.d/mysqld start

四、登录mysql查看权限

[root@explnk-zabbix zabbix-2.2.9]# mysql -ugl -p

Enter password:

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

Your MySQL connection id is 1

Server version: 5.5.32 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> select * from mysql.user\G

*************************** 3. row ***************************

Host:

User: gl

Password: *5F70B50879BD3B98CB5A945D3A6A7C92F41B8AE8

Select_priv: Y

Insert_priv: Y

Update_priv: Y

Delete_priv: Y

Create_priv: Y

Drop_priv: Y

Reload_priv: Y

Shutdown_priv: Y

Process_priv: Y

File_priv: Y

Grant_priv: Y

References_priv: Y

Index_priv: Y

Alter_priv: Y

Show_db_priv: Y

Super_priv: Y

Create_tmp_table_priv: Y

Lock_tables_priv: Y

Execute_priv: Y

Repl_slave_priv: Y

Repl_client_priv: Y

Create_view_priv: Y

Show_view_priv: Y

Create_routine_priv: Y

Alter_routine_priv: Y

Create_user_priv: Y

Event_priv: Y

Trigger_priv: Y

Create_tablespace_priv: Y

ssl_type:

ssl_cipher:

x509_issuer:

x509_subject:

max_questions: 0

max_updates: 0

max_connections: 0

max_user_connections: 0

plugin:

authentication_string: NULL

3 rows in set (0.00 sec)

六、perfect

参考blog：http://my.oschina.net/leejun2005/blog/76140