HasAndBelongsToMany in CakePHP

Question

I have three Models with the associated properties:

Links Model:

var $belongsTo = array('LinkCategory');

LinkCategory Model:

var $hasMany = array('Link');
var $hasAndBelongsToMany = array('User');

User Model

var $hasAndBelongsToMany = array('LinkCategory');

With that, I would expect the following to get me all the link categories for the user.

$user_link_categories = $this->LinkCategory->find('all', array('conditions' => array('User.id' => 1)));

However, it dies with: Unknown column 'User.id' in 'where clause' Query: SELECT LinkCategory.id, LinkCategory.title, LinkCategory.created, LinkCategory.modified FROM link_categories AS LinkCategory WHERE User.id = 1

I am new to CakePHP, but not MVC. In my mind, this should work given my associations. Have I missed something or does this just not work in CakePHP for some reason.

Answer 1

LinkCategory doesn't have a field User.id... as a matter of fact, the way User.id has a period in the middle suggests id is a field which belongs to User.

Since LinkCategory belongsTo a User it probably has a field user_id, so theoretically this should work:

$user_link_categories = $this->LinkCategory->find('all', array('conditions' => array('user_id' => 1)));

If this still doesn't work it means your DB tables don't have columns to support these relationships and you'll need to read more about associations to get to the bottom of that.

Personally, though, I think you're going backwards. You're trying to find a LinkCategory based on their associated User, but you can't use a field from another model (User) like this in a simple find() (on LinkCategory).

Instead you should find the User with an id of '1', then - since a User belongsTo a LinkCategory - read that's User's LinkCategory. Again, I'm rusty, but I'm thinking it would look a little like this...

$user = $this->User->find('first', array('conditions' => array('Article.id' => 1)));
pr($user);

... make that recursive (see here) and $user should load your LinkCategory as well.