python - Directional Many-to-many self referencing ORM in SQLAlchemy using Association Pattern -


i tried quite while , didn't find solution specific problem, apologize in advance.

suppose have following model tables users , follows:

     ________         src      ________      |  user  |-1------------*-| follow |      |--------|                |--------|      | id     |                | src_id |     |        |                | dst_id |     |        |                | string |     |________|-1------------*-|________|                       dst

notice that there different semantics depending on foreign keys.

i'm trying achieve through "association pattern" (described here), can work. looks this:

class follow(base):     __tablename__ = 'follows'     #     src_id = column(biginteger, foreignkey('users.id'), primary_key=true)     dst_id = column(biginteger, foreignkey('users.id'), primary_key=true)      src = relationship("user", back_populates="followers", foreign_keys=[src_id])     dst = relationship("user", back_populates="followees", foreign_keys=[dst_id])      kind = column(string(16))  class user(base):     __tablename__ = 'users'      name = column(string(20))      followers = relationship("uuedge", primaryjoin="user.id==uuedge.dst_id")     followees = relationship("uuedge", primaryjoin="user.id==uuedge.src_id")

is possible? doing wrong?

cheers

p.s.

similar question not answer mine:

how can achieve self-referencing many-to-many relationship on sqlalchemy orm referencing same attribute?

this how implemented follower relationship in project using join table.

followers = table(     'followers', metadata,     column('user_id', integer,         foreignkey('users.user_id'), primary_key=true),     column('follower_id', integer,         foreignkey('users.user_id'), primary_key=true), )  class user(base):      __tablename__ = 'users'      user_id = column(integer, primary_key=true)      followers = relationship(         'user', secondary=followers, cascade='all', lazy='dynamic',         primaryjoin=followers.c.user_id == user_id,         secondaryjoin=followers.c.follower_id == user_id)   # following! user = session.query(user).get(..) follower = user() user.followers.append(follower)

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