How do I write a join query across multiple tables in CakePHP?

Solution 1:

$markers = $this->Marker->find('all', array('joins' => array(
    array(
        'table' => 'markers_tags',
        'alias' => 'MarkersTag',
        'type' => 'inner',
        'foreignKey' => false,
        'conditions'=> array('MarkersTag.marker_id = Marker.id')
    ),
    array(
        'table' => 'tags',
        'alias' => 'Tag',
        'type' => 'inner',
        'foreignKey' => false,
        'conditions'=> array(
            'Tag.id = MarkersTag.tag_id',
            'Tag.tag' => explode(' ', $this->params['url']['q'])
        )
    )
))); 

as referred to in nate abele's article: link text

Solution 2:

I'll be honest here and say that you'll probably be a lot happier if you just create a function in your model, something like getTopicVotes() and calling query() there. Every other solution I can think of will only make it more complicated and therefore uglier.

Edit:

Depending on the size of your data, and assuming you've set up your model relations properly (Topic hasMany Items hasMany Votes), you could do a simple find('all') containing all the items and votes, and then do something like this:

foreach ($this->data as &$topic)
{
    $votes = Set::extract('/Topic/Item/Vote', $topic);
    $topic['Topic']['vote_count'] = count($votes);
}

Two things are important here:

1. If you have a lot of data, you should probably forget about this approach, it will be slow as hell.
2. I've written this from my memory and it might not look like this in real life and/or it may not work at all :-)

Solution 3:

You can easily set the "recursive" property on a find() query.

$result = $this->Topic->find('all', array('recursive' => 2));

Alternatively, you can use the Containable behavior in your model. Then you can use:

$this->Topic->contain(array(
    'Item',
    'Item.Vote',
));

$result = $this->Topic->find('all');

or

$result = $this->Topic->find('all', array(
    'contain' => array(
        'Item',
        'Item.Vote',
    ),
));

Solution 4:

What you need is recursive associations support, which is not possible with stock CakePHP currently.
Although it could be achieved using some bindModel trickery
or an experimental RecursiveAssociationBehavior.

Both of these solutions will either require you to use extra code or rely on a behaviour in your application but if you resist the temptation to write pure SQL code, you'll be rewarded with being able to use Cake`s pagination, auto conditions, model magic etc..