Why my relation ship return always null with PHP Phalcon?

I try to use relationShip ManyToMany with PHP Pahlcon 3.4

My models :

use PhalconMvcModel;

class Societe extends Model
{
public $id;
public $nom;
public $adresse1;
public $adresse2;
public $code_postal;
public $ville;
public $pays;
public $siret;
public $numero_tva;
public $created_at;
public $updated_at;

public function initialize()
{
    $this->setSource('societies');
    $this->hasMany(
        'id',
        'StatementModelSocietesBanques',
        'societe_id'
    );
}

and Banque :

use PhalconMvcModel;

class Banque extends Model
{
public $id;
public $nom;

public function initialize()
{
    $this->setSource('banques');
    $this->hasMany(
        'id',
        'StatementModelSocietesBanques',
        'banque_id'
    );
}

and relation :

use PhalconMvcModel;

class SocietesBanques extends Model
{

public $id;

public $societe_id;

public $banque_id;

public function initialize()
{
    $this->setSource('societes_banques');
    $this->belongsTo(
        'societe_id',
        'StatementModelSociete',
        'id'
    );

    $this->belongsTo(
        'banque_id',
        'StatementModelBanque',
        'id'
    );
}

I can save in table societes_banques, but not get data

In my controller, I get my Societe object :

$societe = Societe::findFirst($id);

After, I try to get SocietesBanques data with :

$societe->societesBanques

This line return me NULL

If I try :

$societe->getSocietesBanques()

I have the error :

The method 'getSocietesBanques' doesn't exist on model 'StatementModelSociete'

I do same thing as Phalcon documentation

Can you help me? what is my fault?

Answer

Because you didn’t specified an alias during relation declaration.

class Societe extends Model
{
public function initialize()
{
    $this->setSource('societies');
    $this->hasMany(
        'id',
        'StatementModelSocietesBanques',
        'societe_id', [
            'alias' => 'societesBanques', // 4th parameter as array
        ]
    );
}

And after that, you can call magic method getSocietesBanques().