I'm sure this information exists on these forums, but I have searched and have been unable to find an answer.

Is it possible to do an in-memory sort of an EntityCollection using a field on a related entity? The field is not mapped as a related field if that makes a difference.

So assume I have a collection of orders and want to sort them by the customer's CustomerCreatedDate field. I know how to do this on the database side, but not in-memory.

(Adapter 2.6.8.903)

Thanks,

Phil

Hi Phil,

I can think in these ways:

Using MemberPredicate and ENtityView2

IPredicateExpression filter = new PredicateExpression();
MemberPredicate relatedFilter = new MemberPredicate(OrderEntity.MemberNames.Customer, MemberOperator.Any, (CustomerFields.CustomerId == "ALFKI"));          
filter.Add(relatedFilter);

EntityView2<OrderEntity> filteredOrders = new EntityView2<OrderEntity>(orders, filter);

Using Entitviews with a custom property

// __LLBLGENPRO_USER_CODE_REGION_START CustomEntityCode
public string CustomerName
{
    get
    {
        string toReturn = string.Empty;
        if (Customer != null)
        {
            toReturn = Customer.CompanyName;
        }
        return toReturn;
    }
}
// __LLBLGENPRO_USER_CODE_REGION_END

IPredicateExpression filter = new PredicateExpression();
filter.AddWithAnd(new EntityProperty("CustomerName") % "A%" );
EntityView2<OrderEntity> filteredOrders = new EntityView2<OrderEntity>(orders, filter);

Using Linq2Objects (.Net 3.5)

var filteredOrders = from o in orders
                     where o.Customer.CompanyName.StartsWith("A")
                     select o;

Hey David,

I was asking about sorting, not filtering.

Or do they work similarly?

Thanks,

Phil

Using Linq2Objects, and assuming for example you have fetched orders collection along with the related customer entity, then you can in-memory sort the orders collection on a field inside the customer entity as follows:

            var q = from o in orders
                     orderby o.Customers.PostalCode
                     select o; 

Then the new sorted collection can be found using q.ToList();

Sorry--I should have mentioned that Linq is not an option, as we are still on Visual Studio 2005 and .net 2.0/3.0.

Is there a non-linq method?

In that case, this is the way:

// __LLBLGENPRO_USER_CODE_REGION_START CustomEntityCode
public string CustomerName
{
    get
    {
        string toReturn = string.Empty;
        if (Customer != null)
        {
            toReturn = Customer.CompanyName;
        }
        return toReturn;
    }
}
// __LLBLGENPRO_USER_CODE_REGION_END

SortExpression sorter = new SortExpression();
sorter.Add(new SortClause(new EntityProperty("CustomerName"), null, SortOperator.Ascending));           
EntityView2<OrderEntity> orderedOrders = new EntityView2<OrderEntity>(orders, sorter);