I am developing a small application. I am using ASP.NET 8 with FastEndpoints and EntityFrameworkCore with the Sqlite Provider as a backend.

I have an endpoint where I create a reservation. For the reservation I need the corresponding vehicle. In the request I have the VehicleId.

This is the code-snippet from the endpoint:

VehicleModel? requestedVehicle = await _database.VehicleModels.FindAsync(req.Vehicle);
if (requestedVehicle is null)
{
    _logger.LogWarning("Could not find Vehicle {VehicleId}", req.Vehicle);
    await SendNotFoundAsync(ct);
    return;
}

Even tough the requested vehicle is in the database, I always get null back. I tried capturing this in the following Screenshot. In the top-right you can see the database content with the id. On the lower you can see the request object with the requested vehicleId.

Debugger – Request (VehicleId) does exist in database

This happens even when I change from FindAsync to await _database.VehicleModels.FirstOrDefaultAsync(x => x.Id == req.Vehicle);

Any ideas why this is happening?

This is my model class:

[StronglyTypedId(Template.Guid)]
public partial struct VehicleModelId {}

public sealed record VehicleModel
{
    public VehicleModelId Id { get; set; }

    public string Name { get; set; } = string.Empty;

    public List<ReservationModel> Reservations { get; set; } = new();
}

And this is my DatabaseContext:

public class DatabaseContext : IdentityDbContext<UserModel, IdentityRole<Guid>, Guid>
{
    public DatabaseContext(DbContextOptions<DatabaseContext> options) : base(options) { }

    public DbSet<ReservationModel> ReservationModels { get; set; } = null!;

    public DbSet<VehicleModel> VehicleModels { get; set; } = null!;
    public DbSet<UserModel> UserModels { get; set; } = null!;

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        
        modelBuilder.Entity<UserModel>()
            .HasMany(u => u.ReservationsMadeByUser)
            .WithOne(u => u.ReservationMadeByUser);
        
        modelBuilder.Entity<ReservationModel>()
            .HasKey(u => u.Id);
        modelBuilder.Entity<ReservationModel>()
            .Property(x => x.Id)
            .HasConversion(x => x.Value, x => new ReservationId(x));
        
        modelBuilder.Entity<VehicleModel>()
            .HasKey(u => u.Id);
        modelBuilder.Entity<VehicleModel>()
            .Property(x => x.Id)
            .HasConversion(x => x.Value, x => new VehicleModelId(x));
        modelBuilder.Entity<VehicleModel>()
            .HasMany(x => x.Reservations)
            .WithOne(x => x.VehicleReserved);
    }
}

And this is the request class I am using for the endpoint. The modelbinding works, I just wanted to include this:

public record CreateReservationRequest
{
    [Required]
    public DateOnly StartDateInclusive { get; set; }
    
    [Required]
    public DateOnly EndDateInclusive { get; set; }
    
    [Required]
    public Guid ReservedBy { get; set; }
    
    [Required]
    public VehicleModelId Vehicle { get; set; }
}

Note: I am using StronglyTypedId, but as you can see I added all the conversions

As described above, I already tried switching from FindAsync to FirstOrDefaultAsync as i thought there would be an error with the FindAsync method.

I also tried changing the Guid from lowercase to Uppercase (all possible permutations in the databse and the request) but also got no luck there.