Calling SubmitChanges on DataContext does not update database

In C# ASP.NET MVC application I use Link to SQL to provide data for my application. I have got simple database schema like this:

In my controller class I reference this data context called Model (as you can see on the right side of picture in properties) like this:

private Model model = new Model();

I've got a table (List) of Series rendered on my page. It renders properly and I was able to add delete functionality to delete Series like this:

public ActionResult Delete(int id) {
    model.Series.DeleteOnSubmit(model.Series.SingleOrDefault(s => s.ID == id));
    model.SubmitChanges();
    return RedirectToAction("Index");
}

Where appropriate action link looks like this:

<%: Html.ActionLink("Delete", "Delete", new { id=item.ID })%>

Also create (implemented in similar way) works fine. However edit does not work. My edit looks like this:

public ActionResult Edit(int id) {
    return View(model.Series.SingleOrDefault(s => s.ID == id));
}

[HttpPost]
public ActionResult Edit(Series series) {

    if (ModelState.IsValid) {
        UpdateModel(series);

        series.Title = series.Title + " some string to ensure title has changed";
        model.SubmitChanges();

        return RedirectToAction("Index");
    }
    return View(series);
}

I have controlled that my database has a primary key set up correctly. I debugged my application and found out that everything works as expected until the line with model.S开发者_StackOverflow社区ubmitChanges();. This command does not apply the changes of Title property(or any other) against the database.

Please help.

EDIT: If I add this line: model.Series.Attach(series); just before model.SubmitChanges(); there is no change - edits still does not reflect to database. The instance passed to Edit method as a parameter is already attached to the data context model.

EDIT: Code of view that belongs to method Edit:

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" 
Inherits="System.Web.Mvc.ViewPage<TVSeriesInfoApp.Models.Series>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Edit
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

<h2>Edit</h2>

<% using (Html.BeginForm()) {%>
    <%: Html.ValidationSummary(true) %>

    <fieldset>
        <legend>Fields</legend>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Title) %>
        </div>
        <div class="editor-field">
            <%: Html.TextBoxFor(model => model.Title) %>
            <%: Html.ValidationMessageFor(model => model.Title) %>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Seasons) %>
        </div>
        <div class="editor-field">
            <%: Html.TextBoxFor(model => model.Seasons) %>
            <%: Html.ValidationMessageFor(model => model.Seasons) %>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Stars) %>
        </div>
        <div class="editor-field">
            <%: Html.TextBoxFor(model => model.Stars) %>
            <%: Html.ValidationMessageFor(model => model.Stars) %>
        </div>

        <p>
            <input type="submit" value="Save" />
        </p>
    </fieldset>

<% } %>

<div>
    <%: Html.ActionLink("Back to List", "Index") %>
</div>

</asp:Content>

This is what our Edit Action would look like (Adjusted for your model):

[HttpPost]
public ActionResult Edit(int id, Series series)
{
    Series updatingSeries = model.Series.Single(s => s.ID == id);

    try
    {
        TryUpdateModel(updatingSeries);
        model.SubmitChanges();

        return RedirectToAction("Details", new { id = updatingSeries.ID });
    }
    catch
    {
        return View(updatingSeries);
    }
}

This can happen because the ModelState might not be valid in some cases. Have you done something to the View? Can you also post your View Code here please?

First, never ever "delete" with HTTP GET (this is exactly what you're doing with Html.ActionLink("Delete", "Delete", new { id=item.ID }).

As for edits, you first have to Attach your instance to the DataContext.