Using Group By clause with Entity Framework in C# .Net

I have made sample for count of cities in country.

1. Create System App_Code folder

2. Add .dbml file in App_Code folder

3. Drag and drop table from your database using server explorer

4. Add Connection string in web.config

5. Add new page with datacontext to refer your table

6. Follow the steps give below

Please refer following sample:

HTML

<div>
    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
        <Columns>
            <asp:BoundField HeaderText="Country" DataField="Country" />
            <asp:BoundField HeaderText="Count of cities" DataField="Count_of_cities" />
        </Columns>
    </asp:GridView>
</div>

Namespace:

using System.Linq;
using LINQ;

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}

protected void BindGrid()
{
    using (DataClassesDataContext dc = new DataClassesDataContext())
    {
        var res = from c in dc.Customers
                    group c.City by c.Country into g              
                    select new 
                    { 
                        Country = g.Key, 
                        Count_of_cities = g.ToList().Count() 
                    };                      

        GridView1.DataSource = res.ToList();
        GridView1.DataBind();
    }
}

Screenshot

Structure of solution explorer

Customer Table

Output