11.2. Ordering List

A common pattern in many applications is the use of ordered collections. For instance, consider a simple to-do list application with multiple lists, each containing an (ordered) set of items. We might start with the following schema:

todo_list_table = Table(
    'todo_list', metadata,
    Column('name', Unicode(255), primary_key=True))

todo_item_table = Table(
    'todo_item', metadata,
    Column('id', Integer, primary_key=True),
    Column('list_name', None, ForeignKey('todo_list.name')),
    Column('list_position', Integer),
    Column('value', Unicode))