Brilliant. Thanks for that lightning response, workaround and fix.
I'll give the code a spin.
On 28 Jan, 23:19, Michael Bayer <[EMAIL PROTECTED]> wrote:
> hi there -
>
> the bug is fixed in r4103, the test below will work as stated. Or you
> can stick with the workaround for now.
>
> On Jan 28, 2008, at 4:03 PM, Phil Coombs wrote:
>
>
>
>
>
> > Hi
>
> > I'm a Python and SA newbie investigating SA for a project using
> > Postgres. I have a database schema that I want to point SA at then be
> > able to write my Python code.
>
> > I'm working with a version of the basic_association example to keep
> > things simple. I want to have unique auto generated ids on my tables
> > (surrogate primary keys) but also want to have primary keys defined
> > over the entities' actual attributes. I want to have surrogate keys on
> > my tables so that I can use them instead of the full priamary keys
> > when writing joins to keep the SQL brief. In some cases (e.g. the
> > association table) I'm defining the primary key in terms of surrogate
> > primary keys rather than copy over the full primary key from the
> > associated tables.
>
> > When I run the code (below) I get AttributeError: 'Order' object has
> > no attribute '_instance_key'.
>
> > Please can someone help me setup SA to work in this example?
>
> > Thanks in advance
>
> > Phil
>
> > Postgress DDL
> > ----------------------
> > create table orders (
> > order_id Serial ,
> > o_customer_name text not null,
> > o_order_date timestamp not null,
> > primary key (o_customer_name, o_order_date) using index ,unique
> > (order_id);
>
> > create table items (
> > item_id Serial ,
> > it_description text not null,
> > it_price Numeric(8,2) not null,
> > primary key (it_description) using index, unique (item_id) using
> > index);
>
> > create table order_items (
> > oi_order_id Integer not null,
> > oi_item_id Integer not null,
> > oi_price Numeric(8,2) not null,
> > primary key (oi_order_id, oi_item_id) using index);
>
> > Python
> > ----------
> > [SNIP] setup and connect string
>
> > engine = create_engine(connectString, echo=False)
> > metadata = MetaData(engine)
>
> > orders_table = Table('orders', metadata, autoload=True)
> > items_table = Table('items', metadata, autoload=True)
> > orderitems_table = Table('order_items', metadata,
> > Column('oi_order_id', Integer,
> > ForeignKey('orders.order_id'),
> > primary_key=True),
> > Column('oi_item_id', Integer,
> > ForeignKey('items.item_id'),
> > primary_key=True),
> > autoload=True
> > )
>
> > class Order(object):
> > def __init__(self, customer_name, order_date):
> > self.customer_name = customer_name
> > self.order_date = order_date
>
> > class Item(object):
> > def __init__(self, description, price):
> > self.description = description
> > self.price = price
>
> > class OrderItem(object):
> > def __init__(self, item, price=None):
> > self.item = item
> > self.price = price or item.price
>
> > mapper(Order, orders_table, properties = {
> > 'id' : orders_table.c.order_id,
> > 'customer_name' : orders_table.c.o_customer_name,
> > 'order_date' : orders_table.c.o_order_date,
> > 'order_items' : relation(OrderItem)
> > })
>
> > mapper(Item, items_table, properties = {
> > 'id' : items_table.c.item_id,
> > 'description' : items_table.c.it_description,
> > 'price' : items_table.c.it_price
> > })
>
> > mapper(OrderItem, orderitems_table, properties = {
> > 'order_id' : orderitems_table.c.oi_order_id,
> > 'item_id' : orderitems_table.c.oi_item_id,
> > 'price' : orderitems_table.c.oi_price,
> > 'item' : relation(Item)
> > })
>
> > Session = sessionmaker(bind=engine, autoflush=True,
> > transactional=True)
> > session = Session()
>
> > session.save(Item('Item A', 10.99))
> > session.save(Item('Item B', 8))
> > session.save(Item('Item C', 4))
> > session.save(Item('Item D', 1))
> > session.flush()
>
> > def item(name):
> > return session.query(Item).filter_by(description=name).one()
>
> > order = Order("cust1", datetime.now())
> > order.order_items.append(OrderItem(item('Item A')))
> > order.order_items.append(OrderItem(item('Item B'),10))
> > order.order_items.append(OrderItem(item('Item C')))
>
> > session.save(order)
> > session.commit()- Hide quoted text -
>
> - Show quoted text -
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to sqlalchemy@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en
-~----------~----~----~----~------~----~------~--~---
