Multiple models to same table

How about you use one single Model for all of your vehicles and then use QueryScope for every single type of vehicles.

Examples :

• Fetching all vehicles

Vehicle::all();

• Cars :

Vehicle::cars()->get();

and so on...

Hum... @RachidLaasri you gave me a possible solution but I think that you didn't get the point. To deal with different types of vehicles, I want to have a Model for each type. I want to avoid a hundred of conditions to get the right behavior of each vehicle's type.

Thank you!

Either way you'll end up at the same result. If you don't want a single model with 20 query scopes, use a trait. If you want to models, then extend the base model which in essence will just perform a query scope.

Or use repositories that wrap your queries in the same way.

@joruro Eloquent doesn't handle things like this, but such override will work for you:

(assuming type is the column that determines which model to use, you could obviously store real class name instead, so the code would be simpler)

// Vehicle model
public function newFromBuilder($attributes = [], $connection = null)
{
    switch (array_get((array) $attributes, 'type')) {
        case 'car':
            $model = new Car;
            break;
        case 'motorcycle':
            $model = new Motorcycle;
            break;
        case 'truck':
            $model = new Truck;
            break;
        default:
            $model = $this->newInstance();
    }

    $model->exists = true;

    $model->setRawAttributes((array) $attributes, true);

    $model->setConnection($connection ?: $this->connection);

    return $model;
}

With this you can call Vehicle::all() and get beatiful collection just like you wanted with single query:

[
    Truck {..},
    Car {..},
    Car {..},
    Motorcycle {..},
    Vehicle {..}, // if type was neither of motorcycle, car or truck
    ...
]

Mind that I never tested this, so play with it, call the relations and so on, for it may lead to unexpected results somewhere else.

@joruro Sounds like a perfect candidate for a polymorphic relationship.

Hi, thank you for your help. I am very grateful.

@JarekTkaczyk your solution is until now the best that I found but the best of the best would be a solution provided natively by Laravel. May be, next versions of Laravel will have some kind of support for these situations.

@martinbean A polymorphic relation works very well with models that have their own table. Not my case where all the models represent the same table and inherit the same model.

@joruro You could create individual model classes that extend the base Vehicle, but each apply a global query scope limiting results to the relevant “type”. For example:

class Truck extends Vehicle
{
    protected static function boot()
    {
        static::addGlobalScope(new VehicleTypeScope('truck'));

        parent::boot();
    }
}

Now when you perform find() or similar operations, you’ll only get models of that type:

$trucks = Truck::all();

@JarekTkaczyk I changed the code

    public function newFromBuilder($attributes = [], $connection = null)
    {
        $entryClassName = array_get((array) $attributes, 'type');
        if(strpos($entryClassName, '\\') !== 0) {
            $entryClassName = __NAMESPACE__ . '\\' . $entryClassName;
        }

        if (class_exists($entryClassName)
            && is_subclass_of($entryClassName, self::class)
        ) {
            $model = new $entryClassName;
        } else {
            $model = $this->newInstance();
        }

        $model->exists = true;
        $model->setRawAttributes((array) $attributes, true);
        $model->setConnection($connection ?: $this->connection);

        return $model;
    }

Just used @martinbean's approach to this and it works a treat. Cheers.

@ANDREWCLARK - Hey, a bit late to this conversation but I like the look of @martinbean's approach too. However, I've been trying it but can't get Factories to work. Taking something like your example above I want to be able to do:

factory(App\Truck::class)->create();

But that gives me this error in Tinker:

PHP Notice:  Undefined index: App/Truck in .../vendor/laravel/framework/src/Illuminate/Database/Eloquent/Model.php on line 241

How can I create Factories for different types of Vehicle?

Edit: I could do factory(App\Vehicle::class)->state('truck')->create() and define a different state in the VehicleFactory for each type of Vehicle, but I'd rather a more intuitive approach (and shorter Factory files) if there is one.

@FORRESTEDW - Currently facing the same issue. But I guess that's a compromise that you'll have to accept, after all your custom class only filters retrieved results from the parent class... I'm also on the search for a more intuitive approach!

For anyone who comes across this thread, check out the Single Table Inheritance package for Laravel: https://github.com/calebporzio/parental

For the factories to work, just extend the base factory and merge the definition with the parent class:

class CarFactory extends VehicleFactory
{
		public function definition()
    	{
        		return array_merge(parent::definition(), [
            			'attribute1' => 'fake value',
            			'attribute2' => 'fake value',
        		]);
		}

		// You may also use configure() to perform afterMaking and afterCreating actions
}

Note: in your models, you will need to manually specify the table for Eloquent:

class Car extends Vehicle
{
 		protected $table = 'vehicles';

		// Optionally add your global scope to boot() as explained by martinbean
}