使用Laravel的Eloquent删除hasManyThrough关系行

Question

I have three models, Advertiser , PtcAd , and PtcCampaign . When deleting a Advertiser I want to delete all related PtcAds and PtcCampaigns . The Advertiser has many PtcCampaigns through PtcAds .

Advertiser Model

use SoftDeletes;

protected $dates = ['deleted_at'];

public function ptcAds()
{
    return $this->hasMany('App\PtcAd');
}

public function ptcCampaigns()
{
    return $this->hasManyThrough('App\PtcCampaign', 'App\PtcAd');
}

public function delete()
{
    $this->ptcAds()->delete();
    // I'VE TRIED WITH AND WITHOUT THIS
    $this->ptcCampaigns()->delete();

    return parent::delete();
}

PtcAd Model

use SoftDeletes;

protected $fillable = ['advertiser_id', 'title'];

protected $dates = ['deleted_at'];

public function advertiser()
{
    return $this->belongsTo('App\Advertiser');
}

public function ptcCampaigns()
{
    return $this->hasMany('App\ptcCampaign');
}

public function delete()
{
    $this->ptcCampaigns()->delete();

    return parent::delete();
}

PtcCampaign Model

use SoftDeletes;

public $timestamps = false;

protected $fillable = ['ptc_ad_id', 'clicks'];

protected $dates = ['paused_at', 'deleted_at'];

public function ptcAd()
{
    return $this->belongsTo('App\PtcAd');
}

My tests:

public function test_delete_advertiser()
{
    $advertiser = factory(Advertiser::class)->create();

    $ptcAd = factory(PtcAd::class)->create(['advertiser_id' => $advertiser->id]);

    $ptcCampaign = factory(PtcCampaign::class)->create(['ptc_ad_id' => $ptcAd->id]);

    $this->assertTrue($advertiser->delete());
    $this->assertFalse(Advertiser::all()->contains($advertiser));
    $this->assertFalse(PtcAd::all()->contains($ptcAd));

    // THE FOLLOWING TEST DOESN'T WORK!
    $this->assertFalse(PtcCampaign::all()->contains($ptcCampaign));
}

// ALL OF THE FOLLOWING TESTS WORK!
public function test_delete_ad()
{
    $ptcAd = factory(PtcAd::class)->create();

    $ptcCampaign = factory(PtcCampaign::class)->create(['ptc_ad_id' => $ptcAd->id]);

    $this->assertTrue($ptcAd->delete());
    $this->assertFalse(PtcAd::all()->contains($ptcAd));
    $this->assertFalse(PtcCampaign::all()->contains($ptcCampaign));
}

The $this->assertFalse(PtcCampaign::all()->contains($ptcCampaign)) in the test_delete_advertiser() test fails, why?

I have more tests to make sure all the relationships work so I really don't know what could possibly be wrong. My next attempt would be to make foreach in the Advertiser's delete() method but maybe there's something simpler and I want to understand why this doesn't work.

Answer 1

It looks the problem is with the sequence of delete statement.

Try by changing the sequence like below:

public function delete()
{
    $this->ptcCampaigns()->delete();

    $this->ptcAds()->delete();

    return parent::delete();
}

Answer 2

You can use Laravel's Model Events ( deleting ) to delete related models like this:

class Advertiser extends Eloquent
{
    public function ptcAds()
    {
        return $this->hasMany('PtcAd');
    }

    // this is a recommended way to declare event handlers
    protected static function boot() {
        parent::boot();

        static::deleting(function($adv) { // before delete() method call this
             $adv->ptcAds()->delete();
             // do the rest of the cleanup...
        });
    }
}

// Same for PtcCompaigns

class PtcAd extends Eloquent
{
    public function ptcCompaigns()
    {
        return $this->hasMany('PtcCompaigns');
    }

    // this is a recommended way to declare event handlers
    protected static function boot() {
        parent::boot();

        static::deleting(function($ptc_ad) { // before delete() method call this
             $ptc_ad->ptcCompaigns()->delete();
             // do the rest of the cleanup...
        });
    }
}

Hope this helps!