Mysql User Creation

CREATE USER 'luke'@'x.x.x.x' IDENTIFIED BY 'testpassword';
Use % for wildcard host. Accessible from any locations. E.g 
CREATE USER 'luke'@'%' IDENTIFIED BY 'testpassword';

Setting user password

SET PASSWORD FOR 'root'@'localhost'

Deleting a user

drop user 'luke'@'x.x.x.x';



Checking MySQL Password

Sometimes you forget the password for a user. This is annoying as hell. You have a list of old passwords but you are able to log in as root You can use the following to confirm if the password is correct: 

mysql> select if(password('randompassword')=password, 'YES', 'NO') from mysql.user where user='lukeslinux';
+-----------------------------------------------------+
| if(password('randompassword')=password, 'YES', 'NO') |
+-----------------------------------------------------+
| YES                                                 |
+-----------------------------------------------------+
1 row in set (0.00 sec)