Problem with between join for sqlalchemy orm relation.
- by Gary van der Merwe
I'm trying to create a relation that has a between join. Here is a shortish example of what I'm trying to do:
#!/usr/bin/env python
import sqlalchemy as sa
from sqlalchemy import orm
from sqlalchemy.engine.base import Engine
from sqlalchemy.ext.declarative import declarative_base
metadata = sa.MetaData()
Base = declarative_base(metadata=metadata)
engine = sa.create_engine('sqlite:///:memory:')
class Network(Base):
__tablename__ = "network"
id = sa.Column(sa.Integer, primary_key=True)
ip_net_addr_db = sa.Column('ip_net_addr', sa.Integer, index=True)
ip_broadcast_addr_db = sa.Column('ip_broadcast_addr', sa.Integer, index=True)
# This can be determined from the net address and the net mask, but we store
# it in the db so that we can join with the address table.
ip_net_mask_len = sa.Column(sa.SmallInteger)
class Address(Base):
__tablename__ = "address"
ip_addr_db = sa.Column('ip_addr', sa.Integer, primary_key=True,
index=True, unique=True)
Network.addresses = orm.relation(Address,
primaryjoin=Address.ip_addr_db.between(
Network.ip_net_addr_db,
Network.ip_broadcast_addr_db),
foreign_keys=[Address.ip_addr_db])
metadata.create_all(engine)
Session = orm.sessionmaker(bind=engine)
Network()
I you run this, you get this error:
ArgumentError: Could not determine relation direction for primaryjoin condition
'address.ip_addr BETWEEN network.ip_net_addr AND network.ip_broadcast_addr', on relation Network.addresses.
Do the columns in 'foreign_keys' represent only the 'foreign' columns in this join condition ?
The answer to that question is Yes, but I cant figure out how to tell it that
