rendered paste body self.movie_table = Table('movie', self.metadata, autoload=True) #mapper(Movie, self.movies_table) self.category_table = Table('movie_category', self.metadata, autoload=True) mapper(MovieCategory, self.category_table) self.movies_categories_table = Table('movies_categories', self.metadata, Column('mid', Integer, ForeignKey("movie.mid")), Column('mcid', Integer, ForeignKey("movie_category.mcid"))) moviemapper = mapper(Movie, self.movie_table) moviemapper.add_property('categories', relation(MovieCategory, secondary=self.movies_categories_table, lazy=False))