Question

I’m confused about how DQL works, and really need some help here.

I have three tables, called “Band”, “Agent”, and “BandAgent”.

BandAgent is the middle table for a Many-to-many relationship, containing agent_id and band_id.

How can I retrieve all Agents related to a specific band_id using a DQL statement?

---

EDIT

This code works, but I don’t know if it is the right way to do it. Echos to the screen all associated Agents related to a Band by BandID:

//$band is a Band Table Row
$bandAgentTable = Doctrine_Core::getTable('BandAgent');
$agentTable = Doctrine_Core::getTable('Agent');

$bandAgentTable = $bandAgentTable->findByBandId($band->getId());
foreach ($bandAgentTable as $bandAgent) {   
    $agent = $agentTable->findById($bandAgent['agent_id']);
    echo $agent[0]['name'];
}

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EDIT 2

I ended up reading a heck of a lot about Doctrine, and ended up moving away from Magic Finders. The following code is what I ended up doing for my Many-to-Many issue, if anyone is interested:

public function getRelatedAgents() {
$q = Doctrine_Query::create()
   ->from('Band b')
   ->leftJoin('b.Agents a')
   ->where('b.id = ?', $this->getId());
$bands = $q->fetchArray();
return $bands[0]['Agents'];
}

Answer 1

Doctrine offers Magic Finders.

$bandAgentTable = Doctrine_Core::getTable('BandAgent');    
$bandAgentTableSearch = $bandAgentTable->findByBand($band);

This will search the column Band in the table BandAgent and match it with the variable $band.

The basic pattern for the finder
methods are as follows:
findBy%s($value) or
findOneBy%s($value). The %s can be a
column name or a relation alias. If
you give a column name you must give
the value you are looking for. If you
specify a relationship alias, you can
either pass an instance of the
relation class to find, or give the
actual primary key value.

Update: In response to your edit, you can also search on two columns together.

$agent = $bandAgentTable->findByBandIdAndId($band->getId(), $bandAgent['agent_id']);