print a linq group by query in asp.net mvc4

Question

I have a problem when trying to print a linq query, after making the following query

var cargaDatos = (from rs in DB.C_gestcobcanalvendsem
                            group rs by new { rs.semana } into s
                            orderby s.Key
                            select new 
                            {
                              Semana = s.Key,
                              TotalDeuda = s.Sum(x => x.Credito)
                             }
                           ).ToList();

      return View(cargaDatos);

I try to print with the recommended way

<% foreach (var item in Model) { %>
    <tr>
        <td>
            <%: Html.DisplayFor(modelItem => item.Semana) %>
        </td>

<% } %>

or similar forms, but i don't find the form to print it. (possibly i'm doing something wrong but can not find the right way to manipulate the linq query whit 'group by clause').

regards

How did you define your Model for the View, you are returning an anonymous type from your controller. — Habib, Jul 14 '14 at 17:25
I'm not defining directly (like php), ¿i need to define a type of? (and how to do this) — h40s4m4, Jul 14 '14 at 17:34

James P · Accepted Answer · 2014-07-14T19:17:58.113

0

You need to create a ViewModel such as:

//Call it whatever you want
public class ViewModel 
{
    // use whatever types Key and TotalDeuda are
    public int Semana { get; set; }
    public double TotalDeuda { get; set; }
}

Then you can use it in your linq query to make a strongly typed List:

   // Rest of linq as in your question
   select new ViewModel {
                           Semana = s.Key,
                           TotalDeuda = s.Sum(x => x.Credito)
                        }).ToList();

Then at the top of your View you need to put a @model or inherits declaration to define the model as strongly typed, set to IEnumberable<ViewModel> - or whatever you called the class.

Then you can show the two properties in your loop just using:

<%foreach (var item in Model)
    {  %>
<tr><td><%=item.Semana%></td>
<td><%=item.TotalDeuda%></td></tr>
<%} %>

Also it's easier using Razor syntax if you are able to look in to this. See article here for more info.

edited Jul 14 '14 at 19:17

answered Jul 14 '14 at 18:28

James P

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i see, but, i can't use my actual class for this? or for each "grouped query" I must create a new model? – h40s4m4 Jul 14 '14 at 19:17
Yes, it is best to create a ViewModel if you are generating a result set that differs from your original class. For more information on ViewModels see [Here](http://stackoverflow.com/questions/11064316/what-is-viewmodel-in-mvc), Or [Here](http://stackoverflow.com/questions/16548376/asp-net-mvc-how-exactly-to-use-view-models) - also for a more in depth look at how you can pass data in MVC see [here](http://www.codeproject.com/Articles/687061/Multiple-Models-in-a-View-in-ASP-NET-MVC-MVC). – James P Jul 14 '14 at 19:22
Thanks a lot, it's easier in symfony jajaja, close – h40s4m4 Jul 14 '14 at 19:24

print a linq group by query in asp.net mvc4

1 Answers1