Updating data with Entity framework

Question

In the project I’m developing, MVC5, Entity 6, I’m simply not being able to update the data.

The Code:

zyon.TB_Cliente.Attach(cliente);
zyon.Entry(cliente).State = System.Data.Entity.EntityState.Modified;
zyon.SaveChanges();

Which works when I create the database through the project, is not working when I connect to an existing database.

Data is saved normal with:

zyon.TB_Cliente.Add(cliente);
zyon.SaveChanges();

But the update does not occur. = T

Answer 1

Three alternatives. Use specific version instead of Object:

zyon.Entry<TB_Cliente>( client ).State = System.Data.Entity.EntityState.Modified;

Go straight to ChangeTracker make the change:

zyon.ChangeTracker.Entries<TB_Cliente>().First( x => x.Entity == client ).State = System.Data.Entity.EntityState.Modified;

Or, if it is a particular code snippet, and you are already tired of the somewhat mysterious EF errors, do both:

zyon.TB_Cliente.Attach( client );
zyon.Entry( client ).State = System.Data.Entity.EntityState.Modified;
zyon.ChangeTracker.Entries<TB_Cliente>().First( x => x.Entity == client ).State = System.Data.Entity.EntityState.Modified;
zyon.SaveChanges();

---

For documentation, DbContext.Entry(object) should be a valid way to access the properties of a tracked or attached object, and change State to Modified would be all necessary to force the data UPDATE. But from time to time does not scroll, simply.

The generic version, if you want to update several objects in an immediate way (and outside the official transaction!):

public void DetachedUpdate(T obj)
{
    using (var context = new Context())
    {
        context.Set<T>().Attach(obj);
        context.ChangeTracker.Entries<T>().First(e => e.Entity == obj).State = EntityState.Modified;
        context.SaveChanges();
    }
}

Answer 2

I’ll do it like this, see if it helps you.

[Authorize]
[HttpPost]
[ControleDeAcesso(TipoAcao.Normal)]
public ActionResult Detalhar(string btnSubmit, Memo model)
{
    // Verifica se o modelo é válido, senão retorna para a View
    if (!ModelState.IsValid)
        return View(model);

    using (var db = new ERPContext()) // Cria o contexto de conexão
    {
        var memo = db.Memo.Find(model.MemoID); // Busco o registro
        var retorno = FlexGestor.Helpers.EntidadeBaseExt.ValidarRegistro(memo, TipoAcao.Gravar); // Valido o registro
        if (retorno != "")
        {
            TempData["MsgRetornoError"] = retorno;
            return RedirectToAction("Index", "Home");
        }

        if (btnSubmit != "Excluir")
            UpdateModel(memo);  // Se não for exclusão, pego os dados do model e jogo no registro buscado
        Helpers.EntidadeBaseExt.AtribuirValores(memo, btnSubmit); // Função interna minha
        db.Entry(memo).State = EntityState.Modified; // Seto como modificado 
        db.SaveChanges(); // Salvo

        // Retorno para a view conforme ação original
        if (btnSubmit == "Excluir")
            return RedirectToAction("Index", controller);

        return RedirectToAction("Detalhar", controller, new { id = model.MemoID });
    }
}

Answer 3

Place your code inside a Modelstate and add break point in the method to see if there is an error with the edited data.

It would look something like this:

     if (ModelState.IsValid)
    {
       zyon.TB_Cliente.Attach(cliente);
       zyon.Entry(cliente).State = System.Data.Entity.EntityState.Modified;
       zyon.SaveChanges();
    }
    return View(cliente); 

Answer 4

You should first check if your entity ID is filled and then you could try this way doing a treatment in the object state, where Dbbase is your context and Tentity your entity, in the client case.

public void Atualiza(TEntity entidadeEntity)
{
    if (DbBase.Entry(entidadeEntity).State == EntityState.Detached)
        DbBase.Set<TEntity>().Attach(entidadeEntity);

    DbBase.Entry(entidadeEntity).State = EntityState.Modified;
    DbBase.SaveChanges();
}