Data binding directly to a store query (DbSet, DbQuery, DbSqlQuery) is not supported. Instead populate a DbSet with data,

Data binding directly to a store query (DbSet, DbQuery, DbSqlQuery) is not supported. Instead populate a DbSet with data, for example by calling Load on the DbSet, and then bind to local data. For WPF bind to DbSet.Local. For WinForms bind to DbSet.Local.ToBindingList()

When I tried to run the application I got the following error it was resolved. You need to use the result of the query as datasource for your combobox.

In this example, I want to bind the list countries to a combobox using c# .net.

private void LoadCountries()
        {
            var countries = (from c in db.Orders
                             select new { c.ShipCountry }).Distinct().ToList();
           cboCountry.DataSource = countries;
           cboCountry.ValueMember = "shipcountry";
           cboCountry.DisplayMember = "shipcountry";       }