发生System.Data.Entity.Infrastructure.DbUpdateException

Question

So I have made a custom controller by parsing objects in a model to a database in my project and inside that controller, there is a post method called Edit which includes the database fields such as Id, Title, Description, FileName, FileType, FileSize, Author,DateUploaded

In the edit html view, I removed some elements because all I want to edit is "Title" and "Description" and I have also removed the fields in the edit method in the controller I created.

To explain that;

public ActionResult Edit([Bind(Include = FileSharing "Id,Title,Description,FileName,FileType,FileSize,Author,DateUploaded")] FileSharing fileSharing)

into:

public ActionResult Edit([Bind(Include = "Id,Title,Description")] FileSharing fileSharing)

When I try to edit a title or description. It will give a exception error saying

System.Data.Entity.Infrastructure.DbUpdateException' occurred in EntityFramework.dll but was not handled in user code

Why am I getting this error and how can I get around it?

Edit method

public ActionResult Edit([Bind(Include = "Id,Title,Description")] FileSharing fileSharing)
    {
        if (ModelState.IsValid)
        {
            try
            {
                db.Entry(fileSharing).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            catch (Exception)
            {
                ViewBag.EditFail = "Error editing file details.";
            }
        }
        return View(fileSharing);
    }

Answer 1

Here's how I handle that exception.

private Exception HandleDbUpdateException(DbUpdateException dbu)
        {
            var builder = new StringBuilder("A DbUpdateException was caught while saving changes. ");
            if (!(dbu.InnerException is System.Data.Entity.Core.UpdateException) ||
                !(dbu.InnerException.InnerException is System.Data.SqlClient.SqlException))
            {
                try
                {
                    foreach (var result in dbu.Entries)
                    {
                        builder.AppendFormat("Type: {0} was part of the problem. ", result.Entity.GetType().Name);
                    }
                }
                catch (Exception e)
                {
                    builder.Append("Error parsing DbUpdateException: " + e);
                }
            }
            else
            {
                var sqlException = (System.Data.SqlClient.SqlException)dbu.InnerException.InnerException;
                for (int i = 0; i < sqlException.Errors.Count; i++)
                {
                    builder.AppendLine("    SQL Message: " + sqlException.Errors[i].Message);
                    builder.AppendLine("    SQL procedure: " + sqlException.Errors[i].Procedure);
                }
            }

            string message = builder.ToString();
            return new Exception(message, dbu);
        }

Then at least the exception has more relevant information, which probably makes it easy for you to figure out what's wrong (like some DB validation issue).