I have two databases tables,

CREATE TABLE `company` (
`id` int(11) NOT NULL,
`company_id` int(11) NOT NULL,
`company_name` varchar(255) NOT NULL,
PRIMARY KEY (`id`),
KEY `company_id` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1

CREATE TABLE `employee` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`emp_id` int(11) NOT NULL,
`emp_name` varchar(255) NOT NULL,
`cmp_id` int(11) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1

Now I want to add Bi-Directional OneToOne Join(on cmp_id which is non-primary key column).

How do I design my entities?

What have you tried so far?