Question

Hope that someone out there can help with this!

I’ll give an example based on the standard Order–>OrderLine–>Product rather than the actual situation to make it easier to explain!

Basically, I want to run a query that returns all orders for which there is an order line containing a TV. Simple enough:

IEnumerable<Order> orders;
          using (var context = new DataContext())
          {
              var source =
                  context.Orders.Include("OrderLines").Include(
                      "OrderLines.Product");

              orders= source.Where(o => o.OrderLines.Where(ol => ol.Product.Name == "TV")).ToList();
          }
          return orders;

This works in the sense that I get the correct collection of Order entities, but when I use look at each Order’s collection of OrderLines it contains all OrderLines not just those containing at TV.

Hope that makes sense.

Thanks in advance for any help.

Answer 1

I does make sense in that the query is fulfilling your original criteria “to return all orders for which there is an order line containing a TV”, each order will of course have all the orderlines. The filter is only being used to select the Orders, not the OrderLines.

To retrieve just the OrderLines containing TV from an Order you’d use the filter again, thus:

var OrderLinesWithTV = order.OrderLines.Where(ol => ol.Product.Name == "TV");