Updating multiple objects using EntityFramework in ASP.NET MVC 3 using the TryUpdateModel method

Question

I am struggling with ASP.NET MVC3 when trying to update data through the Entity Framework. The process is as follows:

I have this model:

public class Bet { public string BetID { get; set; } public int FixtureID { get; set; } public string Better { get; set; } public int GoalsHome { get; set; } public int GoalsGuest { get; set; } public virtual Fixture { get; set; } } 

In the controller, I filter the table through the where clause to get only records matching the user:

  [HttpGet] public ActionResult Index() { var user = User.Identity.Name; var model = _db.Bets.Where(t => t.Better == user); return View(model); } 

The view consists of two parts that take care of the table headers, and the other - about all user bids:

 <fieldset> <legend>Bets</legend> <table> <tr> <th> Kickoff </th> <th> Home Team </th> <th> Guest Team </th> <th> Group </th> <th> Bet </th> </tr> @Html.EditorFor(m => m) //this is resolved in an self made EditorTemplate </table> 

The EditorTemplate:

 @model Betting.Models.Bet <tr> <td> @Html.DisplayFor(modelItem => Model.Fixture.Kickoff) </td> <td> @Html.DisplayFor(modelItem => Model.Fixture.HomeTeam) </td> <td> @Html.DisplayFor(modelItem => Model.Fixture.GuestTeam) </td> <td> @Html.DisplayFor(modelItem => Model.Fixture.Group) </td> <td> @Html.TextBoxFor(modelItem => Model.GoalsHome, new { style = "width: 30px" }): @Html.TextBoxFor(modelItem => Model.GoalsGuest, new { style = "width: 30px" }) </td> @Html.HiddenFor(modelItem => Model.FixtureID) </tr> 

Back to the controller I'm trying to update the model:

  [HttpPost] public ActionResult Index(FormCollection collection) { var user = User.Identity.Name; var model = _db.Bets.Where(t => t.Better == user); TryUpdateModel(model); _db.SaveChanges(); return RedirectToAction("Index"); } 

This is absolutely nothing. Entity Framework will not update the database at all. I even divided the table so that the received bid tags in the html file were distinguishable (note the [index] before the name value:

  <input data-val="true" data-val-number="The field GoalsHome must be a number." data-val-required="The GoalsHome field is required." name="[1].GoalsHome" style="width: 30px" type="text" value="3" />: <input data-val="true" data-val-number="The field GoalsGuest must be a number." data-val-required="The GoalsGuest field is required." name="[1].GoalsGuest" style="width: 30px" type="text" value="0" /> 

Can someone tell me why the Entity Framework is not updating the database? Is there something wrong with displaying the object?

Answer 1

I had the same problem. MSDN may be rather confusing on this point, but halfway down the page states that if you create your POCO objects without proxycreationenabled, you will have to invoke the detected changes before calling savechanges.

 TryUpdateModel(model); _db.DetectChanges(); _db.SaveChanges(); 

Answer 2

Well, it seems to me that I found a way to update the database without using the TryUpdateModel method. Since the items sent to the html column are different, I can add a parameter to the controller method that contains the bids that I get from the view. Then I iterate over the results from the database and update the fields that change using the values ​​of the bid fields from the view:

  [HttpPost] public ActionResult Index(FormCollection collection, List<Bet> bets) { var user = User.Identity.Name; var model = _db.Bets.Where(t => t.Better== user); int i = 0; foreach (var bet in model) { Bet the_Bet= bets.Find( delegate(Bet _bet) { return _bet.BetID == bet.BetID; }); bet.GoalsHome= the_Bet.GoalsHome; bet.GoalsGuest= the_Bet.GoalsGuest; i++; } _db.SaveChanges(); return RedirectToAction("Index"); } 

I wonder if there is a way to make it work with the TryUpdateModel method.