Laravel 4 - foreign key constraint fails - php

Question

I have the following relations:
Discount:
<?php
class Discount extends Eloquent {
protected $table = 'discount';
public $timestamps = true;
public function title()
{
return $this->hasOne('Translation', 'labelId', 'titleLabelId')->where('languageId', T::getLang())->first()['phrase'];
}
public function titles()
{
return $this->hasMany('Translation', 'labelId', 'titleLabelId');
}
}
?>
Translation:
<?php
class Translation extends Eloquent {
protected $table = 'translations';
public $timestamps = false;
protected $fillable = array('phrase', 'languageId', 'labelId');
public function language()
{
return $this->belongsTo('Language', 'languageId');
}
public function label()
{
return $this->belongsTo('Label', 'labelId');
}
}
?>
Label:
<?php
class Label extends Eloquent {
protected $table = 'label';
public $timestamps = false;
protected $fillable = array('key');
public function translations()
{
return $this->hasMany('Translation', 'labelId', 'id');
}
}
?>
There are three database tables with the following columns:
Discount:
id | titleLabelId
Translation:
id | languageId | labelId
Label:
id
The problem: I'd like to create a title (translation) and associate it with the discount. Here's what I've tried:
$discount = new Discount;
/*create a new label*/
$labelKey = Label::max('key') + 1;
$label = new Label(array('key' => $labelKey));
$label->save();
/*create a new title (and associate it with the label)*/
$title = new Translation(
array(
'phrase' => $input['title'],
'languageId' => 3,
'labelId' => $label->id
));
$title->save();
$discount->save();
$discount->titles()->save($title);
Apparently, the $discount->titles()->save($title); part doesn't work. The title is only attached to the discount if I do it manually: $discount->titleLabelId = $label->id. Is there a way to do it using the ORM?

Answer 1

In your Discount Model, do you have your relationship set up to use the proper table and foreign key?
class Discount extends Eloquent
{
public function titles()
{
return $this->belongsTo('Translation', 'translations', 'titleLabelId');
}
}

Answer 2

When trying to associate one model with another through a defined relationship in Eloquent, you should use the associate() method rather than the save() method.
$discount->titles()->associate($title);
Before this happens though, you should be sure to call the save() method on anything that has been altered or is new.