Laravel检索多行数据

Question

I have a 3-way relationship query. I want to get a session for a movie which also has a cinema.

I have access to the movie id as $id passed into the parameter. I want to find the cinemas which have that movie id.

Here is my controller:

public function ticketpage($id)
{
    $movie = Movie::find($id);
    $cinemas = Cinema::all();
    $sessions = Session::all();
    $query = Session::where('movie_id', "$id")->get();
    $count = count($query)-1;


    $cinemaId = $query[$count]['cinema_id'];
    $cinemaRow = Cinema::where('id', "$cinemaId")->get();

    return view('movies/ticketpage/index')
        ->with('cinemas', $cinemas)
        ->with('sessions', $sessions)
        ->with('movie', $movie)
        ->with('cinemaRow', $cinemaRow);
}

As you can see I'm not really sure how I can use my $query (retrieving all sessions with that movie id) to retrieve all the rows of that session that have that cinema id.

I've used $query[count]['cinema_id] but it will only return one value, the value of the last row. I want it to return the values of all the rows. I tried using a for loop but didn't have much success.

Thanks for your help!

Answer 1

First of all, I would assume the following schema and relationship is being set up.

| Movie | Cinema | Session   |
| ----- | ------ | --------- |
| id    | id     | id        |
|       |        | cinema_id |
|       |        | movie_id  |

This is how I will fetch the cinemas that is playing the movie by its movie_id based on your statement:

I have access to the movie id as $id passed into the parameter. I want to find the cinemas which have that movie id. .

public function ticketpage($id)
{
    // Get all Cinema which has the Session with the Movie.id
    $cinemas = Cinema::whereHas('sessions', function ($query) use ($id) {
        $query->where('movie_id', $id);
    })->get();

    return view('movies/ticketpage/index', [
        'cinemas' => $cinemas
    ]);
}

Answer 2

try this :

public function ticketpage($id)
{
$movie = Movie::find($id);
$cinemas = Cinema::all();
$sessions = Session::all();
$query = Session::select('cinema_id')->where('movie_id', $id)->get();
//$count = count($query)-1;


//$cinemaId = $query[$count]['cinema_id'];
//$cinemaRow = Cinema::where('id', $cinemaId)->get();
$cinemaRow = Cinema::whereIn('id', $query)->get();

return view('movies/ticketpage/index', compact('cinemas', 'sessions', 'movie', 'cinemaRow'));

// No need for all the 'withs'
//return view('movies/ticketpage/index')
//    ->with('cinemas', $cinemas)
//    ->with('sessions', $sessions)
//    ->with('movie', $movie)
//    ->with('cinemaRow', $cinemaRow);
}

Answer 3

Replace these two in your code and try it should work :

$query = Session::select('cinema_id')->whereMovie_id($id)->get();
$cinemaWithSession = Cinema::whereId($query)->get();

Answer 4

If you have the movie id and there is a movie_id column in cinemas table you can retrieve cinemas using this query:

public function ticketpage($id)
{
    $cinemas = Cinema::where('movie_id',$id)->get();
    return view('movies.ticketpage.index',compact('cinemas'));
}