It *sounds* like exactly what I'm looking for, but when I try a simple
example, it doesn't seem to work:
>>>
>>> ol=OrderDetail()
>>> ol.productid = 'DININGCHAIR'
>>> DBSession.query(Product).with_parent(ol).all()
15:21:57,688 INFO [sqlalchemy.engine.base.Engine.0x...d3d0] BEGIN
15:21:57,694 INFO [sqlalchemy.engine.base.Engine.0x...d3d0] SELECT
products.productid AS products_productid, products.brand AS
products_brand, products.vendorsku AS products_vendorsku,
products.stockeditem AS products_stockeditem,
products.packagesplittype AS products_packagesplittype,
products.packagecomponent AS products_packagecomponent,
products.productgroup AS products_productgroup, products.productfamily
AS products_productfamily, products.productsubfamily AS
products_productsubfamily, products.description AS
products_description, products.regular AS products_regular,
products.commissiontype AS products_commissiontype,
products.replacementcost AS products_replacementcost, products.sale AS
products_sale, products.onhand AS products_onhand, products.onorder AS
products_onorder, products.imageurl AS products_imageurl,
products.special AS products_special, products.featured AS
products_featured, products.newproduct AS products_newproduct
FROM products
WHERE products.productid = %(param_1)s
15:21:57,694 INFO [sqlalchemy.engine.base.Engine.0x...d3d0]
{'param_1': None}
[]
>>>
I had expected the bind variable param_1 to equal the fk of
'DININGCHAIR'
What am I missing?
On Feb 26, 2:50 pm, Michael Bayer <mike...@zzzcomputing.com> wrote:
> On Feb 26, 2010, at 1:48 PM, Kent wrote:
>
>
>
> > I'm certain sqlalchemy's got a function call in its guts that I was
> > about to recreate from scratch, so I'm hoping you can spare me the
> > trouble.
>
> > I'm trying to construct the foreign key where clause and from clause
> > needed to populate a relation.
>
> > I'd explain how I got here, but might take several days, so instead,
> > is there a function call to help me?
>
> > In other words, I've got an object, for example an order:
>
> > ===================================
>
> > orderdetail_table = Table("orderdetails",metadata,
> > Column("orderid", Unicode, ForeignKey('orders.orderid'),
> > primary_key=True),
> > Column("lineid", Integer, primary_key=True),
> > Column("saleprice", Numeric, nullable=False),
> > Column("productid", Unicode(255),
> > ForeignKey('products.productid'), nullable=False)
> > )
>
> > product_table = Table("products", metadata,
> > Column("productid", Unicode(255), primary_key=True),
> > Column("brand", Unicode(255),
> > ...
> > )
>
> > class Order(object):
> > pass
>
> > class OrderDetail(object):
> > pass
>
> > # ---------------------------- OrderDetail
> > -------------------------------------------------------- #
> > orderdetail_mapper = mapper(OrderDetail, orderdetail_table,
> > allow_null_pks=False,
> > properties=dict(product=relation(Product,
> > cascade='refresh-expire,expunge', #don't save
> > changes to Product
> > lazy=False)))
>
> > =====================
>
> > Say the 'product' relation is not populated on a *transient*
> > OrderDetail object that I will not be issuing a session flush() for
> > (there are errors detected.. but that's the long story).
>
> > I want to populate the transient OrderDetails 'product' attribute with
> > the detached product.
>
> > I assume there is no way a refresh of the 'product' attribute will
> > accomplish this since the parent obj is transient (which would really
> > be what I want), so I am also assuming I'll need to build the pk
> > clause and issue a session.query.get().
>
> > Since this is dynamic code (accepting any sqla object), I need to
> > dynamically construct that pk clause and from clause based on the
> > mapper's RelationProperty. In other words, use _foreign_keys to
> > construct this ?
>
> > But I imagine there is already a function call that will get me what I
> > want.
>
> > In the end, for this example, I'd want to dynamically build
> > session.query(Product).filter( * pk clause based on fks *)
>
> > Is there a function that can get me most everything I want (return the
> > pk clause) or must I build that up myself, and if myself, do you
> > recommend the RelationProperty's _foreign_keys attribute as the
> > starting point?
>
> > Thanks in advance, again.
>
> are you perhaps looking for sess.query(Product).with_parent(someorder) ?
> there's an example here:
> http://www.sqlalchemy.org/docs/mappers.html#building-query-enabled-pr...
>
>
>
> > --
> > You received this message because you are subscribed to the Google Groups
> > "sqlalchemy" group.
> > To post to this group, send email to sqlalch...@googlegroups.com.
> > To unsubscribe from this group, send email to
> > sqlalchemy+unsubscr...@googlegroups.com.
> > For more options, visit this group
> > athttp://groups.google.com/group/sqlalchemy?hl=en.
>
>
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to sqlalch...@googlegroups.com.
To unsubscribe from this group, send email to
sqlalchemy+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en.
