Syntax:
PASSWORD(str)

Calculates and returns a password string from the plaintext password
str and returns a string, or NULL if the argument was NULL. This is the
function that is used for encrypting MySQL passwords for storage in the
Password column of the user grant table.

As of MySQL 5.5.3, the return value is a nonbinary string in the
connection character set. Before 5.5.3, the return value is a binary
string.

URL: http://dev.mysql.com/doc/refman/5.5/en/encryption-functions.html

