Laravel显示数据3表

Question

I have the following tables:

flights(id, title, number)
stations(id, title)
flight_price(id, price, flight_id, stationA_id, stationB_id)
flight_station(flight_id, station_id)

flight_station is a pivot table.

My models:

class Flight extends Model
{
    public function stations()
    {
        return $this->belongsToMany('App\Model\Station', 'flight_station', 'flight_id', 'station_id')
    }

    // To attach data
    public function prices()
    {
        return $this->belongsToMany('App\Model\FlightPrice', 'flight_price', 'flight_id', 'stationA_id')
            ->withPivot('price');
    }

    public function price()
    {
        return $this->hasMany('App\Model\FlightPrice', 'flight_id');
    }
}

// Station
class Station extends Model
{
    public function flights()
    {
        return $this->belongsToMany('App\Model\Flight', 'flight_station', 'station_id', 'flight_id');
    }


}

class FlightPrice extends Model
{
    protected $table = 'flight_price';

    public function flights()
    {
        return $this->belongsToMany('App\Model\Flight', 'flight_price');
    }
}

I need the next result (find by id flight):

|stationA_id|stationA_title||stationB_id|stationB_title|price|

Answer 1

Let's say you are trying to retrieve a flight like this:

$flight = Flight::with(['price', 'stations'])->find($id);

This returns a Flight model with the Price and Station models because you eager loaded the relationships.

Now $flight->price will return the Price model associated with the Flight model. If it is not a collection - which I believe is true - the foreach loop has little meaning (or at least not the one you expect). In fact it will loop through the public attributes of the Model class (incrementing, exists, wasRecentlyCreated and timestamps).

So the following piece of code will return 4 booleans.

foreach ($flight->price as $value) {
    dump($value);
}

If you want to return the station identifiers, the station titles and the price for each flight then maybe try something like this:

foreach ($flight->stations as $station) {
    dump($station->id);
    dump($station->title);
}

// I assume the Price model has an attribute named value
dump($flight->price->value)