When I have single table inheritance, how can I use the new 'inline'
polymorphic_load feature to only query a subset of child classes?
from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Parent(Base):
__tablename__ = 'parent'
id = Column(Integer, primary_key=True)
type = Column(String(8), nullable=False)
__mapper_args__ = {
'polymorphic_on': type,
'with_polymorphic': '*'
}
class ChildOne(Parent):
one = Column(String(8))
__mapper_args__ = {
'polymorphic_identity': 'one',
'polymorphic_load': 'inline'
}
class ChildTwo(Parent):
two = Column(String(8))
__mapper_args__ = {
'polymorphic_identity': 'two'
}
if __name__ == '__main__':
e = create_engine('sqlite:///inline.db', echo=True)
Base.metadata.drop_all(e)
Base.metadata.create_all(e)
s = Session(e)
s.add_all([ChildOne(one='hahaha'), ChildTwo(two='lololol')])
s.commit()
for c in s.query(Parent).all():
print(c)
I've tried adding and removing 'with_polymorphic': '*' from the parent
class, but it always queries ChildTwo as well
I feel like I need to set something on ChildTwo to tell it not to load, but
nothing like this is documented
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