ASP NET Entity Framework primary key Duplicate resolution - asp.net

Question

[HttpGet]
public ActionResult Create()
{
Articles article = new Articles();
return View(article);
}
[HttpPost]
public ActionResult Create(Articles article)
{
try
{
article.ViewCount = 0;
article.IPAddress = Request.ServerVariables["REMOTE_ADDR"].ToString();
article.RegistDate = DateTime.Now;
article.RegistMemberID = "admin";
article.ModifyDate = DateTime.Now;
article.ModifyMemberID = "admin";
db.Articles.Add(article);
db.SaveChanges();
if (Request.Files.Count > 0)
{
var attachFile = Request.Files[0];
if (attachFile != null && attachFile.ContentLength > 0)
{
var fileName = Path.GetFileName(attachFile.FileName);
var path = Path.Combine(Server.MapPath("~/Upload/"), fileName);
attachFile.SaveAs(path);
ArticleFiles file = new ArticleFiles();
file.ArticleIDX = article.ArticleIDX;
file.FilePath = "/Upload/";
file.FileName = fileName;
file.FileFormat = Path.GetExtension(attachFile.FileName);
file.FileSize = attachFile.ContentLength;
file.UploadDate = DateTime.Now;
db.ArticleFiles.Add(file);
db.SaveChanges();
}
}
ViewBag.Result = "OK";
}
catch (Exception ex)
{
Debug.WriteLine("Board");
Debug.WriteLine(ex.ToString());
ViewBag.Result = "FAIL";
}
return View(article);
//return RedirectToAction("ArticleList");
}
The controller writes a message. But if you write a message (through a POST request) on a bulletin board, it will work normally when you try to post it the first time. But when you try to post again, it fails. I think the cause is a duplicate primary key.
Please let me know what you can do in case of a duplication of the primary key.
namespace HeadHomePage1.Models
{
public class ArticlesEditViewModel
{
public Articles Article { get; set; }
public List<ArticleFiles> Files { get; set; }
}
}
모델부분입니다.