Hello, Another quick question on .with_polymorhpic() .. :)
When I use inheritance I always subclass a Query object per mapped (child) class, for example :
class QueryRoot(orm.Query):
def available_to_all_children(self):
return self.filter(...)
class RootModel(object):
query = Session.query_property(QueryRoot)
class QueryChild(QueryRoot):
def a_child_filter(self):
return self.filter(...)
class ChildModel(RootModel):
query = Session.query_property(QueryChild)
then the mappers:
mapper(Root, table_root,
polymorphic_on=table_root.c.type_id
)
mapper(Child, table_child,
inherits=Root,
polymorphic_identity='child'
)
it works well, and the ability of sub classing a Query class is very
elegant!
The only "problem" is that when I use something like :Root.query.with_polymorphic([Child]) I would like to be able to use QueryChild filters (so be able to do something like Root.query.with_polymorphic([Child]).a_child_filter()). Sounds logical because Child columns will always be present in the result set (because of the LEFT OUTER JOIN)
How would you do that properly? Wouldn't it be interesting to add an option to .with_polymorphic()? Thanks, Julien -- No trees were killed in the creation of this message. However, many electrons were terribly inconvenienced. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
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