How to store selected item's id into database not the title in ASP.NET MVC

Question

New.cshtml:

<div class="form-group ">
    <b>Brand</b>
    @Html.DropDownListFor(m => m.item.brand, new SelectList(Model.Brandlist, "Name" , "Name"), "Search Brand", htmlAttributes: new { @class = "form-control input-xs", id = "search", style = "width:240px;" })
</div>

Index.cshtml:

foreach (var lst_Item in Model)
{
    <tr>
        <td>@lst_Item.brand</td>
        <td>@lst_Item.category</td>
    </tr>
}

Item's view model:

public class newItemsVM
{
    public IEnumerable<Category> Categorylist { get; set; }
    public IEnumerable<Brand> Brandlist { get; set; }
    public Item item { get; set; }
}

Controller

public ActionResult Save(newItemsVM newItemsVM)
{
    if (newItemsVM.item.id == 0)
    {
        _context.tbl_item.Add(newItemsVM.item);
    }
    else
    {
        var Itemdb = _context.tbl_item.Single(c => c.id == newItemsVM.item.id);
        Itemdb.name = newItemsVM.item.name;
        Itemdb.description = newItemsVM.item.description;
        Itemdb.brand = newItemsVM.item.brand;
        Itemdb.category = newItemsVM.item.category;
        Itemdb.shelfno = newItemsVM.item.shelfno;
        Itemdb.stock = newItemsVM.item.stock;
        Itemdb.price = newItemsVM.item.price;
    }

    try
    {
        _context.SaveChanges();
    }
    catch (System.Data.Entity.Validation.DbEntityValidationException dbEx)
    {
        Exception raise = dbEx;

        foreach (var validationErrors in dbEx.EntityValidationErrors)
        {
            foreach (var validationError in validationErrors.ValidationErrors)
            {
                string message = string.Format("{0}:{1}",
                                               validationErrors.Entry.Entity.ToString(),
                                               validationError.ErrorMessage);

                // raise a new exception nesting
                // the current instance as InnerException
                raise = new InvalidOperationException(message, raise);
            }
        }

        throw raise;
    }

    return RedirectToAction("New", "Item"); ;
}

I want the dropdown list to show all the stored brands' name when selecting a particular brand from the dropdownlist and to show the brand's name in the view page when submit button is clicked.

But I want to store the selected brand's id into database not the name actually.

While in database it's storing the brand's name not the id.

Answer 1

You made mistake in map property of DropDown:

Your Brand look like follows as per my assumption:

Brand.cs

public class Brand
{
  public int Id {get;set;}
  public string Name {get;set;}
}

While supplying your Brandlist to Razor you have to supply both Id and Name

Following your model looks like while supplying to the Razor:

newItemsVM model= new newItemsVM();
model.BrandList=new List<Brand>(){ new Brand{Id=1,Name="Brand1"},new {Id=2,Name="Brand2"}};
return View(model);

Now in razor page in Dropdown you have to map both Id and Name like follows:

@Html.DropDownListFor(m => m.item.brand, new SelectList(Model.Brandlist, "Id" , "Name"), "Search Brand", htmlAttributes: new { @class = "form-control input-xs", id = "search", style = "width:240px;" })

after above changes you will get brand id at the time of Save.

Hope this will work for you!!

Note: Make sure ItemDB entity property brand is an int