实体框架核心加入相关表

Question

I have an MVC app with Entity Framework Core. It doesn't work when I run it (I could have swore it worked before), but it works about half the time when debugging. What did I do wrong with setting up my Models and whatnot? I followed a little step by step guide, but now I can't find it. Sorry if this is a duplicate, I couldn't find the right search keywords to find something similar.

Models/BaseProduct.cs

public abstract class BaseProduct
{
    public int Id { get; set; }
    public string Brand { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public string Model { get; set; }
    [Display(Name = "Main Image")]

    public virtual FileDetails MainImage { get; set; }
    public virtual FileDetails AdditionalImages { get; set; }
    public virtual FileDetails Downloads { get; set; }

}

Models/FileDetails.cs

public class FileDetails
{
    public int Id { get; set; }
    public string FileName { get; set; }
    public string FileDir { get; set; }
    public string FileText { get; set; }

}

Controllers/CompressorController.cs

    public async Task<IActionResult> Index()
    {
        var list = await _context.Compressor.ToListAsync();
        foreach (var compressor in list)
        {
            if (compressor.MainImage == null)
            {
                FileDetails img = new FileDetails(){FileDir = "", FileName =  "NoImage.png", FileText = ""};
                compressor.MainImage = img;
            }
        }
        return View(list);
    }

So sometimes it does a join on the FileDetails table and sometimes it doesn't. The Compressor table (that inherits BaseProduct) has the IDs of the FileDetails table, so it seems like I didn't screw up too much.

Solved:

Issue appears to be with Rider. Ran code in Visual Studio and is consistently working with it.

Answer 1

I couldn't figure out how it applies join sometimes and sometimes not but I am pretty sure that EF Core current version doesn't support Lazy Loading. So, try eager loading;

var list = await _context.Compressor
    .Include(x => x.MainImage)
    .ThenInclude(x => x.AdditionalImages)
    .ThenInclude(x => x.Downloads).ToListAsync();

Answer 2

I modified my code similar to Rainman's suggestion, but that still wasn't working.

var list = await _context.Compressor
    .Include(x => x.MainImage)
    .Include(x => x.AdditionalImages)
    .Include(x => x.Downloads).ToListAsync();

I ran the code with Visual Studio instead of Rider and it seems to be working pretty consistently.