Replace SqlDataSource with EntityDataSource - asp.net

Question

I have a DataGrid (destination) with a countryID column, this is binded to a DropDownList to view the countries. I have countries and countryGroups tables too, where countries.countryGroupId = countryGroups.countryGroupId. The list have to be formatted therefore I use SqlDataSource to get the formatted list:
SELECT c.countryID, cg.countryGroupName+': '+c.CountryName as Name
FROM countries AS c INNER JOIN
countries_groups AS cg ON c.countryGroupID = cg.countryGroupID
ORDER BY cg.Sort, c.CountryName
here's the dropdownlist originally binded to sqldatasource:
<asp:DropDownList ID="ddlCountryID" runat="server" Width="160px" DataSourceID="dsCountries"
AppendDataBoundItems="true" DataTextField="Name" DataValueField="countryID"
SelectedValue='<%# Bind("countryID") %>'>
<asp:ListItem Value="" Text="Select"></asp:ListItem>
</asp:DropDownList>
I would like to replace the SqlDataSource to EntityDataSource for the country field. I created the following ProductionModel
VS2010 has been created the public partial class ProductionEntities : ObjectContext...
I created an EntityDataSource:
<asp:EntityDataSource ID="EntityDataSource1" runat="server"
ConnectionString="name=ProductionEntities"
DefaultContainerName="ProductionEntities" EntitySetName="countries"
Include=""
onquerycreated="EntityDataSource1_QueryCreated"
ContextTypeName="ASPWebApp.Datasource.ProductionEntities">
My question is, what other steps are needed to finalyze the binding with EntityDataSource?
Thanks in advance!
UPDATE:
The solution became to be as follows (thanks to #Gaurav Jain)
protected void ddlCountryID_OnInit(object sender, EventArgs e) {
DropDownList ddlCountryID = sender as DropDownList;
ddlCountryID.DataSource = (from c in db.suppliers_countries
join cg in db.suppliers_countries_groups on c.countryGroupID equals cg.countryGroupID
orderby cg.Sort, c.CountryName
select new {
c.countryID,
Name = cg.countryGroupName + ": " + c.CountryName
});
}
and dropdownlist became to be:
<asp:DropDownList ID="ddlCountryID" runat="server" Width="160px" AppendDataBoundItems="true"
SelectedValue='<%# Bind("countryID") %>' **OnInit="ddlCountryID_OnInit"**
DataTextField="Name" DataValueField="countryID">
<asp:ListItem Value="" Text="Select"></asp:ListItem>
</asp:DropDownList>

Answer 1

you can use this query.
ProductionEntities db = new ProductionEntities();
ddlCountryID.DataSource = (from c in db.countries
join cg in db.countries_groups on c.countryGroupID
equals cg.countryGroupID
select new
{ c.countryID,
Name = cg.countryGroupName + " " + c.CountryName,cg.Sort})
.OrderBy(w => new {w.countryID,w.sort });
ddlCountryID.DataTextField = "Name";
ddlCountryID.DataValueField = "countryID";
ddlCountryID.DataBind();