Syntax:
DROP USER user [, user] ...

The DROP USER statement removes one or more MySQL accounts. To use it,
you must have the DELETE privilege for the mysql database. Each account
is named using the same format as for the GRANT statement; for example,
'jeffrey'@'localhost'. If you specify only the username part of the
account name, a hostname part of '%' is used. For additional
information about specifying account names, see [HELP GRANT].
