<?php

/*
 * Implemenation of hook_field_schema()
 */
function civicrm_contact_ref_field_schema($field) {
    return array(
                 'columns' => 
                 array( 'contact_id' => array( 'type'     => 'int',
                                               'unsigned' => TRUE ,
                                               'not null' => FALSE) )
                 );
    
}