linux系统下mysql跳过密码验证登录和创建新用户

修改MySQL的登录设置： 

# vi /etc/my.cnf 

在[mysqld]的段中加上一句：skip-grant-tables 

例如： 

[mysqld] 

datadir=/var/lib/mysql 

socket=/var/lib/mysql/mysql.sock 

skip-name-resolve 

skip-grant-tables 

保存并且退出vi。 

3．重新启动mysqld 

# /etc/init.d/mysqld restart 

Stopping MySQL: [ OK ] 

Starting MySQL: [ OK ] 

4．登录并修改MySQL的root密码 

# /usr/bin/mysql 

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

Your MySQL connection id is 3 to server version: 3.23.56 

Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the buffer. 

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 ( ‘new-password’ ) WHERE User = ‘root’ ; 
（备注：mysql5.7以上修改密码语句：update mysql.user set authentication_string=password('123qwe') where user='root' and Host = 'localhost';）

Query OK, 0 rows affected (0.00 sec) 

Rows matched: 2 Changed: 0 Warnings: 0 

mysql> flush privileges ; 

Query OK, 0 rows affected (0.01 sec) 

mysql> quit 

Bye 

5．将MySQL的登录设置修改回来 

# vi /etc/my.cnf 

将刚才在[mysqld]的段中加上的skip-grant-tables删除 

保存并且退出vi。 

6．重新启动mysqld 

# /etc/init.d/mysqld restart 

Stopping MySQL: [ OK ] 

Starting MySQL: [ OK ] 
创建新用户
grant all privileges on *.* to root@localhost identified by '123456';