How to implement a self referencing (parent_id) model in cakephp

Question

I have a table called categories. The table holds categories and their sub(subsub)categories...

Its an easy table:

• id
• parent_id
• title

Answer 1

Tree behaviour is overkill for this situation. You just need to set your model up like this:

class Category extends AppModel {

  public $hasMany = array(
    'Children'=>array(
       'className'=>'Category',
       'foreignKey'=>'parent_id'
    )
  );

  public $belongsTo = array(
    'Parent'=>array(
       'className'=>'Category',
       'foreignKey'=>'parent_id'
    )
  );

}

Now, when you do a find() on Category, you'll get two additional Models called Parent (which points to the parent id) and Children (which lists it's children).