First, you can go get my sample. I believe I tackle this scenario.
Basically, I have an IDataReader coming back.
2 ResultSets, 1 for Orders, one for OrderDetails.
I put each Order in a OrderCollection.
Order also has a subcollection property, called AllOrderDetails (which is a
OrderDetailCollection)
Ahhh..
Each OrderDetail has an OrderID on it.
So I use the OrderID to find the correct Order (instance) in the
OrderCollection.
then its something like
if(null!= foundOrder)
{
foundOrder.AllOrderDetails.Add ( new OrderDetail ( --- constructor params
here )
}
else
{
throw new ArgumentNullException("There was supposed to be an order in
the order collection, with an order id of {0}"); // you can work out the
string.Format
}
However, because my sql query (stored proc) is correct I never hit that
exception. But I code for it anyways.
Make sense?
It should be in the example. There is a 1.1 and 2.0 version if you need it.
http://sholliday.spaces.live.com/Blog/cns!A68482B9628A842A!140.entry
A couple of changes since the article was written.
I now do
public OrderCollection : List<Order>
{
}
and
public OrderDetailCollection : List <OrderDetail >
{
}
instead of having List<Order> all over the place, I have a well defined
OrderCollection.
(aka, this is a habit I do now, which is not reflected in the example).
....
I also show how you have objects. controllers (manager classes), and how I
use Layouts to keep the code very very maintainable. (a trick learnt from a
former colleague)
...
Good luck.
[quoted text, click to view] "ITistic" <shawn@itistic.com> wrote in message
news:1188419076.387930.280850@o80g2000hse.googlegroups.com...
> Hi everyone,
>
> Just curious as to how much of you OOP developers are handling this
> scenario. Say I have an Order and OrderItem table. Example schema
> below:
>
> Order
> ==
> order_id int (PK)
> customer_id int
> CreatedOn datetime
> ModifiedOn datetime
>
> OrderItem
> ==
> order_item_id int (PK)
> order_id int (FK)
> quantity int
> description varchar(50)
> unit_price money
> CreatedOn datetime
> ModifiedOn datetime
>
> What I need to do is query the database to display all orders within a
> given date range and display these orders and brief details regarding
> the items belonging to each. In my business object layer I have Order
> and OrderItem objects. I could easily query the database for each
> order and THEN query the database separately for each Order's
> OrderItem objects and this would solve the problem, but performance
> would be horrible. The only idea I've come up with is to create a view
> that contains the fields from the Order table AND the OrderItem table.
> I could then query the view based upon the given date range and then
> write code to transform the view records returned from the view into
> my business objects. I guess I'd use a For loop to loop through the
> records and somehow (multiple ways of handling it) create the proper
> Order objects and populate each Order object's OrderItems with the
> proper items.
>
> I guess what I'm wanting to know is if my solution above is common. If
> not, what are the rest of you doing? It just seems like I can't come
> up with a solution that really makes sense. It seems there has to be a
> better solution. I'm curious as to what the rest of you are doing and
> how you handle this problem between your business object layer and
> data layer.
>
> Any suggestions, comments, concerns, etc. are welcome. Thanks in
> advance for your time and replies.
>
> -- Shawn
>
