Users

grant ALL on <database>. to '<username>'@'<hostname>' identified by '<password>'
GRANT [type of permission] ON [database name].[table name] TO ‘[username]’@'localhost’;
REVOKE [type of permission] ON [database name].[table name] FROM ‘[username]’@‘localhost’;
DROP USER ‘demo’@‘localhost’;
Change a users password : SET PASSWORD FOR 'user-name-here'@'hostname-name-here' = PASSWORD('new-password-here');