Cakephp get longest unmodified entries - cakephp

Question

I have a model A that
$hasMany = array('B' => array('order' => 'B.created DESC'),
'C' => array('order' => 'C.created ASC')
);
So now i want to fetch the 5 most desolated entries of A(B,C) from my database that did not get modified the longest time(including B and C 'modified'-field).
How do i do that?
/EDIT: To explain it in other words:
Assume i have a model User that has information like name, adress, email etc.
A User also has many model Post on his page. And he has many model Other on his page too.
So we have a relationship of 1:n in User:Post and User:Other
Now i want to fetch those 5 User of my User, whose highest 'modified' value (User.modified, Post.modified or Other.modified) is one of they five lowest of all Users.
In other words: The 5 User who did not update their profile for the longest time.

Answer 1

I foresee some data inconsistencies in the future with this technique. I would do it this way.
Add field to user table called lastactivity
In AppController.php add beforeSave function
public function beforeSave() {
$save_data = $this->data;
if(isset($save_data['User']['modified']) || isset($save_data['Post']['modified'] || isset($save_data['Other']['modified']))){
$data = array();
$data['User']['id'] = $this->Auth->user('id');
$data['User']['lastactivity'] = date("Y-m-d H:i:s");
$this->User->save($data);
}
}