[SOLVED] How to give a param from View to Controller?

Issue

I have a really stupid question. I have a foreach loop in my project:

@foreach (var item in Model.HallIndex!)

The foreach gives me all the halls in a cinema + the movies which are scheduled in the future, including the time of the movie. So I get this back from the query to my webapp:

Cinema 1

Now playing:

Next movie: SCREAM (3:00 pm)

Cinema 2:

Now playing:

Next movie: TITANIC (8:30 pm)

Etcetera… I think you get it so far. BUT! I would like to use the Hallnumber to get the result of another query, which gets the movie from the database playing now in each hall. So, I need to get a parameter to the Controller.

Edit

This is what I really try to do, but MovieNow doesn’t work:

Controller:

public async Task<ActionResult<IndexViewModel>> Index(int hallId)
{
   IndexViewModel indexViewModel = new IndexViewModel();
        
   indexViewModel.MovieIndex = MovieIndex();
   indexViewModel.MovieNow = MovieNow(hallId);
   indexViewModel.HallIndex = MovieNext();

   return View(indexViewModel);
}

public Showtime MovieNow(int hallId)
{
return _context.Showtime.FromSqlRaw("SELECT * FROM db.\"Showtime\" S JOIN db.\"Movie\" M ON S.\"MovieId\" = M.\"Id\" WHERE \"StartAt\" < now() AND S.\"HallId\" = {0} ORDER BY \"StartAt\" DESC", hallId).FirstOrDefault();
}

ViewModel:

public class IndexViewModel
{
    public Hall? Hall { get; set; }
    public Movie? Movie { get; set; }
    
    public IEnumerable<Showtime>? MovieIndex { get; set; }
    public IEnumerable<Showtime>? HallIndex { get; set; }
    public Showtime? MovieNow { get; set; }
}

View:

<div class="col-4">
   <div class="text-center index-hall-overview">
   @foreach (var item in Model.HallIndex!)
   {
      <div class="row">
         <p class="index-hall-title">CINEMA @Html.DisplayFor(model => item.HallId)</p>
         <p class="index-hall-now">Now playing: @Html.DisplayFor(m => Model.MovieNow.Movie.Title, item.HallId) </p>
         <p class="index-hall-next"><span class="index-hall-p">Next movie:</span> @Html.DisplayFor(model => item.Movie.Title)
         @{
             var startTime = item.StartAt.ToLocalTime().TimeOfDay.ToString(@"hh\:mm");
         }
         (@Html.DisplayFor(model => startTime))</p>
         </div>
         <hr class="index-hall-hr"/>
         }
    </div>
</div>

If I do this, I get the error:
"PostgresException: 42702: column reference "Id" is ambiguous POSITION: 8"

Solution

As you are joining the Showtime and Movie tables, the SELECT * will return all columns from both tables. And apparently both contain an Id column, so which should be used to fill an Id property?

Solution: limit the columns returned to the one correct table by using SELECT s.*

Answered By – Hans Kesting

Answer Checked By – Robin (BugsFixing Admin)