Association Object pattern example: association table lacks data column
In the documentation about ''The association object pattern'' (http://www.sqlalchemy.org/docs/orm/relationships.html#association-object) it seems the data column is missing in the association table. The whole idea about this pattern is to have an association table with additional columns beyond those which are foreign keys to the left and right tables. But the association table has no extra columns. Further on in the example ''association_object''.data is accessed so it seems that data column is missing in the declarative declaration of the association table.