I see, thank you, Mike.
So, looks like I just wanted strange thing: having class to be distinct
from itself.
Thank you for clarifying!
Dmytro
вт, 25 черв. 2019 о 19:26 Mike Bayer пише:
>
>
> On Fri, Jun 21, 2019, at 7:22 AM, Dmytro Starosud wrote:
>
> Base class A1 contains
On Fri, Jun 21, 2019, at 7:22 AM, Dmytro Starosud wrote:
> Base class `A1` contains `polymorphic_identity` (along with
> `polymorphic_on`), but `Query(A1)`doesn't produce where clause, whereas
> `Query(A2)` (where `A2` is subclass of `A1` with its own
> `polymorphic_identity`) does.
> Tried
Thank you Simon.
I think you're right. I should better ask another question, instead of
enrolling XY problem here (in short I need to add particular filter to each
model).
But let's wrap up with this one. Did I understand correctly that I *cannot*
have two following things simultaneously:
1.
The extra base class is only needed once per inheritance hierarchy. Do
you have a hundred of those? Do you mind if I ask what kind of data
you are storing, and how you are structuring your class hierarchy?
Thanks,
Simon
On Fri, Jun 21, 2019 at 1:30 PM Dmytro Starosud wrote:
>
> Thanks for your
Thanks for your reply!
> you could probably insert another class as the parent of A1, with no
polymorphic identity.
This is what I would like to avoid. Otherwise I would need to write some
metaclass machinery to inject base class for all hundred models I have.
Originally I am going to add this
>From a quick test, this appears to be special behaviour for the base
class in an inheritance hierarchy. If you extend your test like this:
from sqlalchemy import Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Query, configure_mappers
Base class A1 contains polymorphic_identity (along with polymorphic_on),
but Query(A1)doesn't produce where clause, whereas Query(A2) (where A2 is
subclass of A1 with its own polymorphic_identity) does.
Tried looking in docs with no success. I think I am just missing something.
from
