Here's a version which I *think* does what you want. There are a
couple of things that you might want to note.
First, in your paste, Conversation.user1 and Conversation.user2 are
integer columns, but you are assigning User objects to those
properties. That's not the way SQLAlchemy works - you can't assign a
related object directly to the column. In my version below I've
renamed the columns to "userid1" and "userid2" and then created
relationships for "user1" and "user2".
Second, the User.conversations property needs to have "viewonly=True".
It wouldn't make sense for it to be a writable property, because if
you appended a new Conversation to it, SQLAlchemy wouldn't know which
of the userid1 or userid2 columns to update.
####################
import sqlalchemy as sa
import sqlalchemy.orm as saorm
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Conversation(Base):
__tablename__ = 'conversations'
id = sa.Column(sa.Integer(), primary_key=True)
userid1 = sa.Column(
sa.Integer(),
sa.ForeignKey('users.id'),
nullable=False,
)
userid2 = sa.Column(
sa.Integer(),
sa.ForeignKey('users.id'),
nullable=False,
)
user1 = saorm.relationship(
"User",
primaryjoin="Conversation.userid1 == User.id",
)
user2 = saorm.relationship(
"User",
primaryjoin="Conversation.userid2 == User.id",
)
class User(Base):
__tablename__ = 'users'
id = sa.Column(sa.Integer(), primary_key=True)
userName = sa.Column(sa.String(32), unique=True, nullable=False)
conversations = saorm.relationship(
Conversation,
primaryjoin=sa.or_(
id == Conversation.userid1,
id == Conversation.userid2,
),
viewonly=True,
)
if __name__ == '__main__':
engine = sa.create_engine("sqlite:///:memory:", echo="debug")
Session = saorm.sessionmaker(bind=engine)
Base.metadata.create_all(engine)
session = Session()
u1 = User(userName="Alireza")
u2 = User(userName="Amir")
session.add_all([u1, u2])
session.commit()
con = Conversation(user1=u1, user2=u2)
session.add(con)
session.commit()
print u1.conversations
####################
On Sun, Sep 2, 2018 at 3:27 PM Alireza Ayin Mehr
<alireza.dark...@gmail.com> wrote:
>
> Well, it seems weird this way, I only have one userId in my parent class
> which is the source class
>
>
> On Sunday, September 2, 2018 at 6:08:33 AM UTC+4:30, Seth P wrote:
>>
>> In relationship(), foreign_keys refers to the field in the source table, not
>> the destination.
>
> --
> SQLAlchemy -
> The Python SQL Toolkit and Object Relational Mapper
>
> http://www.sqlalchemy.org/
>
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SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
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