[SQLObject] Re: SQLObject

[Ian B. <ia...@co...>]

On Tuesday, September 16, 2003, at 08:20 AM, Mark Mueller wrote:
> Ian --
>
> Very nice job with the SQLObject project.  I am
> considering using it for several projects.
>
> I like to model problems using the BON technique,
> however, most middleware does not map to the program
> space in a way that allows me to go easily from the
> BON diagram to the program.  SQLObject help my by
> hiding the details.
>
> Thanks for all your work.

I'm glad you enjoy it.

You should post questions to the mailing list so that everyone can 
participate, answer, or hear the answer.

> I do have a question.  I have two classes arranged in
> a parent-child (one-to-many) relationship.  I need to
> be able to have my collection in the parent object
> include only a subset of the child items.  (For
> example, a customer's account object that has a
> transactions collection that includes transactions for
> a date range.)  My problem is that the account object,
> automatically, gives me all the transations.  Is there
> a way to filter the child objects?

You have to construct the select yourself, like (untested):

class Account(SQLObject):
     transactions = ForeignKey('Trans')
     def transactionsDuring(self, start=None, end=None):
         query = Trans.q.accountID == self.id
         if start:
             query = AND(query, Trans.q.eventDate > start)
         if end:
             query = AND(query, Trans.q.eventDate < end)
         return Trans.select(query)

   Ian