Htykuut

I have the following entities:

namespace SomeDataAccess

{

  public partial class Patch

  {

      public int PatchID { get; set; }

      public double Number { get; set; }

  }



  public partial class PatchFile

  {

      public int FileID { get; set; }

      public int PatchID{ get; set; }

      public string Name { get; set; }

      public string Type { get; set; }

  }

}

And I have the following api model:

namespace Web_API.Models

{

  [Table("SomeFiles")]

  public class SomeFilesViewModel

  {

      [Key]

      public int FileId { get; set; }

      public int PatchNumber{ get; set; }

      public string Name { get; set; }

      public string Type { get; set; }

  }

}

The GET method is implemented successfully as following:

/ GET: api/SomeFiles/5

[ResponseType(typeof(SomeFileViewModel))]

public async Task<IHttpActionResult> GetSomeFileViewModel(int id)

{

  var patchFile = await _context.PatchFile.FindAsync(id);



  return someFile == null

    ? (IHttpActionResult)NotFound()

    : Ok(new someFileViewModel

    {

        FileId = patchFile.FileID,

        PatchNumber = patch.Number,

        Name = patchFile.Name,

        Type = patchFile.Type,

    });

}

Thus far, I have implemented the PUT method as following:

// PUT: api/SomeFiles

[ResponseType(typeof(void))]

public async Task<IHttpActionResult> PutSomeFileViewModel(SomeFilesViewModel someFileViewModel)

{

  if (!ModelState.IsValid)

      return BadRequest(ModelState);



  var file = new SomeDataAccess.PatchFile

  {

      FileID = someFileViewModel.FileId,

      PatchID = _context.Patch.FirstOrDefault(i => i.Number == someFileViewModel.PatchNumber).PatchID

      // How to get the relavent patch id by having the patch Number?

      Name = someFileViewModel.Name,

      Type = someFileViewModel.Type

  };



  _context.Entry(file).State = EntityState.Modified;



  try

  {

    await _context.SaveChangesAsync();

  }

  catch (DbUpdateConcurrencyException)

  {

      if (!FileExists(file.FileID))

        return NotFound();



    throw;

  }



  return StatusCode(HttpStatusCode.NoContent);

}

And a sample payload:

Sample PayLoad:

{

  "FileId" = 4

  "PatchNumber" = 894

  "Name" = "MyFile.exe"

  Type = "Application"

}

How can I update or add a record to PatchFile entity if I only have the PatchNumber and not the PatchId to prevent conflicted with the FOREIGN KEY constraint?

_context.Patch.FirstOrDefault(i => i.Number == someFileViewModel.PatchNumber).PatchID 

Is above the correct approach? If yes, Is this not making another trip to database? Is there a better approach?

You could add the PatchID to the SomeFilesViewModel along the PatchNumber. Otherwise there will be this extra query to the DB. On the other hand: this might create another possible problem, as the sent data don't have to be accurate and you'll need to check/validate it and that would be another trip to DB.

If you decide to stick with the extra query I would suggest rewriting it as following:

_context.Patch.Where(i => i.Number == someFileViewModel.PatchNumber).Select(i => i.PatchID).FirstOrDefault();

That way you get only the ID from the DB; assuming you don't need to work with other parts of your Patch object.