How have it works the EntityColletion?

Question

Hi

I my project, I have an entity that have an Entity Collection and, I want to filter the colletion.

For example, I do a LINQ that brings an customer and this customer have an EntityColletion with all his orders this customer. I want to filter something orders, Is this possible?

Thanks in Advance.

---

Marcos Aguiar Jr - Brazil

Answer 1

Hi Marcos,

I hope I understood your question correctly.

If you have a handle on the customer, you can issue a query as follows to filter some of the orders
Customer cust = YourMethodToGetACustomer()

foreach (Order o in cust.Orders.Where(x => x.OrderId > 0))
{
      //do something with the order
}

You can use the followng link to get more information on using LINQ to Entities:
http://msdn.microsoft.com/en-us/library/bb738458.aspx


Regards,
Akhil Karkera (MSFT)

Answer 2

Hi Marcos,

If you want to get some customers records and filtered collection of the orders belonging to those customers, you can have a query like this:

var query =
   from c in dc.Customers
   where c.Active == true //some condition
   select new {
      c, 
      orders = from o in c.Orders
                where o.OrderDate > DateTime.Parse("2009-10-01") //filter orders of each customer on some condition
                select o
   };

var customers = query.AsEnumerable().Select(q => q.c);

//now customers will have selected customers and their associated filtered orders

For more details, have a look at this post: How to do a Conditional Include


Regards,

---

Syed Mehroz Alam
My Blog | My Articles