MySQL忘記root密碼

To reset a root password that you forgot (using paths on our system):

[root@host root]#killall mysqld
[root@host root]#/usr/libexec/mysqld -Sg --user=root &

You may have better luck with:

mysqld --skip-grant-tables --user=root

Go back into MySQL with the client:

[root@host root]# mysql
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 1 to server version: 3.23.41

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("newpassword")
-> WHERE user="root";
Query OK, 2 rows affected (0.04 sec)
Rows matched: 2 Changed: 2 Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

mysql> exit;
[root@host root]#killall mysqld

Start MySQL the normal way for your system, and all is good. For Red Hat this is:

/etc/init.d/mysqld start