Automatically deleting related rows in Laravel (Eloquent ORM)

Question

I believe this is a perfect use-case for Eloquent events (http://laravel.com/docs/eloquent#model-events). You can use the "deleting" event to do the cleanup:

class User extends Eloquent
{
    public function photos()
    {
        return $this->has_many('Photo');
    }

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

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

You should probably also put the whole thing inside a transaction, to ensure the referential integrity..

You can actually set this up in your migrations:

$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');

Source: http://laravel.com/docs/5.1/migrations#foreign-key-constraints

You may also specify the desired action for the "on delete" and "on update" properties of the constraint:

$table->foreign('user_id')
      ->references('id')->on('users')
      ->onDelete('cascade');

Note: This answer was written for Laravel 3. Thus might or might not works well in more recent version of Laravel.

You can delete all related photos before actually deleting the user.

<?php

class User extends Eloquent
{

    public function photos()
    {
        return $this->has_many('Photo');
    }

    public function delete()
    {
        // delete all related photos 
        $this->photos()->delete();
        // as suggested by Dirk in comment,
        // it's an uglier alternative, but faster
        // Photo::where("user_id", $this->id)->delete()

        // delete the user
        return parent::delete();
    }
}

Hope it helps.

Relation in User model:

public function photos()
{
    return $this->hasMany('Photo');
}

Delete record and related:

$user = User::find($id);

// delete related   
$user->photos()->delete();

$user->delete();