EF 5, update object gives “A referential integrity constraint violation occurred”

Question

In my model I\'ve got a bunch of domain objects. Now I\'m having a problem when trying to update a User-object. The User has a foreignkey relation to the Role object. When I upd

Answer 1

For the benefit of searchers, I was getting the same error but found a quick fix.

I was loading a class with an FK relationship into the view to be edited. Even with no changes, the FK was being dropped and this error occurred. The fix was to include a hidden field into the Razor view that contained the FK. e.g.

@Html.HiddenFor(model => model.ReleaseInfo.BookId)

Code copied below so you can check if your situation is similar.

Controller Actions

public ActionResult Edit(int id = 0)
        {
            Book book = db.Books.Find(id);
            if (book == null)
            {
                return HttpNotFound();
            }
            ViewBag.Id = new SelectList(db.ReleaseInfo, "BookId", "BookId", book.Id);
            return View(book);
        }

        //
        // POST: /Book/Edit/5

        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit(Book book)
        {
            if (ModelState.IsValid)
            {
                db.Entry(book).State = EntityState.Modified;

                db.SaveChanges();
                return RedirectToAction("Index");
            }
            ViewBag.Id = new SelectList(db.ReleaseInfo, "BookId", "BookId", book.Id);
            return View(book);
        }

Relationships

Book.cs

  public class Book
    {
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }

        [Required]
        [MaxLength(100)]
        public string Title { get; set; }


        public virtual ICollection Authors { get; set; }


        public virtual ReleaseInfo ReleaseInfo { get; set; }


        public virtual ICollection ReReleases { get; set; }

    }

ReleaseInfo.cs

public class ReleaseInfo
    {
        // One to one relationship uses Books Key as Key.
        [Key, ForeignKey("Book")]
        public int BookId { get; set; }

        [DataType(DataType.Date)]
        [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
        public DateTime ReleaseDate { get; set; }


        public virtual Book Book { get; set; }
    }