Hi,

I'm developing my first real object-oriented project, and having some
trouble...

Simple scenario:

DB
Table Orders, Fields: Client, Date
Table OrderDetails, Fields: OrderID, Product, Price, Quantity, Discount

Businness Entity
Order, Fields: Client, Date, TotalQuantity, TotalPrice

How should I fill TotalQuantity and TotalPrice fields???
The first approach is using a view, but I don't want to have businness
logic in the database, nor use aggregate functions.
The second, would be creating those fields in the Orders table, but that
would be a waste of space and code.
The third, would be filling the businness entities in the code itself, but
for that, I would need to load all order details in the memory, and loop for
each one. This is ok when I already need all order details, but in a simple
view of all orders, it's not that good.

I still think the third option is the best. Maybe you can give me a clue.

Thanks,
Bruno Rodrigues.

Why don't you want to use aggregate functions? They'd be far faster and more
effiicient than anything you could code.

"Bruno Rodrigues" <(E-Mail Removed)> wrote in
message news:721DDB3D-578B-4C99-8B32-(E-Mail Removed)...
> Hi,
>
> I'm developing my first real object-oriented project, and having some
> trouble...
>
> Simple scenario:
>
> DB
> Table Orders, Fields: Client, Date
> Table OrderDetails, Fields: OrderID, Product, Price, Quantity, Discount
>
> Businness Entity
> Order, Fields: Client, Date, TotalQuantity, TotalPrice
>
> How should I fill TotalQuantity and TotalPrice fields???
> The first approach is using a view, but I don't want to have businness
> logic in the database, nor use aggregate functions.
> The second, would be creating those fields in the Orders table, but that
> would be a waste of space and code.
> The third, would be filling the businness entities in the code itself,
> but
> for that, I would need to load all order details in the memory, and loop
> for
> each one. This is ok when I already need all order details, but in a
> simple
> view of all orders, it's not that good.
>
> I still think the third option is the best. Maybe you can give me a clue.
>
> Thanks,
> Bruno Rodrigues.

Bruno Rodrigues wrote:
> Hi,
>
> I'm developing my first real object-oriented project, and having
some
> trouble...
>
> Simple scenario:
>
> DB
> Table Orders, Fields: Client, Date
> Table OrderDetails, Fields: OrderID, Product, Price, Quantity,
Discount
>
> Businness Entity
> Order, Fields: Client, Date, TotalQuantity, TotalPrice
>
> How should I fill TotalQuantity and TotalPrice fields???
> The first approach is using a view, but I don't want to have
businness
> logic in the database, nor use aggregate functions.
> The second, would be creating those fields in the Orders table, but
that
> would be a waste of space and code.
> The third, would be filling the businness entities in the code
itself, but
> for that, I would need to load all order details in the memory, and
loop for
> each one. This is ok when I already need all order details, but in a
simple
> view of all orders, it's not that good.
>
> I still think the third option is the best. Maybe you can give me a
clue.

The first. Your database must contain part of Business Logic, whether
you like or not.