sql - How to automatically reflect table relationships in SQLAlchemy or SqlSoup ORM? -

how tell sqlalchemy automatically reflect basic foreign key references references other orm objects , not integer fields?

in both sqlalchemy , it's sqlsoup, table columns reflected automatically , relations can defined manually:

class user(base):     __table__ = metadata.tables['users']     loan = relation(loans) 

...

you can define relationships on sqlsoup classes: >>> db.users.relate('loans', db.loans) 

try magic ) works simple fk relations, , without db schemes

from sqlalchemy import create_engine, metadata sqlalchemy.orm import mapper, relation  engine = create_engine("sqlite://", echo=true)  engine.execute('''     create table foo (         id integer not null primary key,         x integer     )''')  engine.execute('''     create table bar (         id integer not null primary key,         foo_id integer,         foreign key(foo_id) references foo(id)     )''')  metadata = metadata() metadata.reflect(bind=engine)   mappers = { }  repr_name = lambda t: '%s%s' % (t[0].upper(), t[1:])  table in metadata.tables:      cls = none     # 1. create class object     cls_name = repr_name(str(table))     exec("""class %s(object): pass""" % cls_name)     exec("""cls = %s""" % cls_name)      # 2. collect relations fk     properties = {}     c in metadata.tables[table].columns:         fk in c.foreign_keys:             name = str(fk.column).split('.')[0]             properties.update({                 name: relation(lambda: mappers[repr_name(name)]),             })      # 3. map table class object      mapper(cls, metadata.tables[table], properties=properties)       mappers.update({cls_name: cls})  if __name__ == '__main__':     sqlalchemy.orm import sessionmaker      print 'mappers: '     m in mappers.values():         print m      session = sessionmaker(bind=engine)()      foo = foo()     foo.x = 1     session.add(foo)      session.commit()      print session.query(foo).all()      bar = bar()     bar.foo = foo     session.add(bar)     session.commit()      print session.query(bar).all()