On Oct 27, 2008, at 10:43 AM, Adam wrote:
>
> I'm having trouble using in_ to select a bunch of related objects -
> here is what I want:
>
> Quick overview of my model (shortened for simplicity):
> #Autoloaded table defs go here and aren't really important
>
> class Person(object):
> pass
>
> class EMailAddress(object):
> pass
>
> orm.mapper(Person, person_table, properties = {
> 'name': orm.column_property(person_table.c.first_name + " " +
> person_table.c.last_name)
> })
>
> orm.mapper(EMailAddress, email_table, properties = {
> 'person': orm.relation(Person, lazy=False,
> backref=backref('email_addresses', lazy=False))
> })
>
>
>
> I want to be able to do something like this:
> people = [person1, person2, person3]
>
> addresses = Session.query(EMailAddress).filter(Person.in_(people))
>
> When I try it, I get an AttributeError: "type object 'Person' has no
> attribute 'in_'"
>
> I'm running 0.5.0rc2
>
> Is this possible?
The "in_()" operator is not currently implemented for many-to-one-
relation, its a TODO. When it is implemented, it would be
EmailAddress.person.in_(people).
so currently two ways to do it:
Session.query(EmailAddress).filter(or_(*[EmailAddress.person==p for p
in people]))
Session.query(EmailAddress).filter(EmailAddress.person_id.in_([p.id
for p in people]))
note that or_() takes *args, in_() takes a list. Believe it or not
there's a rationale for this.
Also I'd recommend a plain python descriptor for "Person.name" since
it would reduce SQL overhead a bit:
@property
def name(self):
return self.first_name + " " + self.last_name
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