Hi there,
I'm trying to do something pretty weird. I have SQLAlchemy instrumented
classes that extend a class in addition to Base, like so:
class Region(Base, t_Region):
__tablename__ = 'region'
id = Column(
mysql.INTEGER(11),
primary_key=True,
nullable=False,
autoincrement=True,
index=True,
unique=True)
name = Column(
mysql.VARCHAR(64),
nullable=False,
index=True,
default='',
unique=True)
This works great for reads because I can return it anywhere a t_Region is
expected and everything does what it is supposed to.
But now I can't figure out how to do the reverse; for example, I have a
t_Region object, and I want to insert it into the database. So far I've got
this:
mapped = Region(**region.__dict__)
This works, but it lacks elegance as it creates another object.
I also tried region.__class__ = Region, but I got a (obvious) error message:
sqlalchemy.orm.exc.UnmappedInstanceError: Class
'ame.serf_service.models.region.Region' is mapped, but this instance lacks
instrumentation. This occurs when the instanceis created before
sqlalchemy.orm.mapper(ame.serf_service.model
s.region.Region) was called.
I've tried a few attempts at calling mapper() that haven't been fruitful
yet. Is there an elegant way to do this?
Bonus points if it can also handle the recursive case, eg:
class A(Base, t_A):
b = Column(mysql.VARCHAR(20), ForeignKey('b.b'))
b_obj = relationship('B', foreign_keys=[b])
such that if I get a t_A that has a b_obj of type t_B, t_A and t_B will
both get mapped appropriately. I'm happy to do this parsing myself, though.
Thanks for any hints,
Dusty
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.
