give advice me how can I give foreign key relation in php

how can I give foreign key relation?

you can give foreignkey relation by defining "foreignKey" key in your belongsTo array of model file. e.g.

var $belongsTo = array(
   'ContentManagementFile' => array(
   'className' => 'ContentManagementFile',
   'foreignKey' => 'content_management_file_id',
   'conditions' => '',
   'fields' => '',
   'order' => ''
   )
 );