Unable to relate two MySQL tables (foreign keys)
- by KPL
Hello people,
Here's my USER table 
CREATE TABLE IF NOT EXISTS `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(100) NOT NULL,
  `expiry` varchar(6) NOT NULL,
  `contact_id` int(11) NOT NULL,
  `email` varchar(255) NOT NULL,
  `password` varchar(100) NOT NULL,
  `level` int(3) NOT NULL,
  `active` tinyint(4) NOT NULL DEFAULT '1',
  PRIMARY KEY (`id`,`email`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
And here's my contact_info table
CREATE TABLE IF NOT EXISTS `contact_info` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  `email_address` varchar(255) NOT NULL,
  `company_name` varchar(255) NOT NULL,
  `license_number` varchar(255) NOT NULL,
  `phone` varchar(30) NOT NULL,
  `fax` varchar(30) NOT NULL,
  `mobile` varchar(30) NOT NULL,
  `category` varchar(100) NOT NULL,
  `country` varchar(20) NOT NULL,
  `state` varchar(20) NOT NULL,
  `city` varchar(100) NOT NULL,
  `postcode` varchar(50) NOT NULL,
  PRIMARY KEY (`id`,`email_address`),
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
The system uses username to login users.I want to modify it in such a way that it uses email for login. But there's no email_address in users table.
I have added foreign key - email in user table(which is email_address in contact_info).
How should I query database?