> None is going to "update to null". But this is not the same as "empty",
> i.e. the key isn't present in obj.__dict__ - that will amount to a skip.
> When you first create the object, the __dict__ is blank as far as values -
> The "None" only appears there when you first access the scalar attribute.
>
> If I were writing SQLA today, perhaps I'd have been a little more
> draconian-yet-consistent and made non-present attributes raise
> AttributeError, but this is what we have.
>
Well, as it is, that *does* allow for more flexibility, I suppose.
As far as 0.5.7, I confirmed the same issue:
"AssertionError: Dependency rule tried to blank-out primary key column
'orderdetails.orderid' on instance '<OrderDetail at 0x1a757a90>'"
>>> dbord = session.merge(ord)
2010-01-14 03:31:01,807 INFO sqlalchemy.engine.base.Engine.0x...00d0
BEGIN
2010-01-14 03:31:01,808 INFO sqlalchemy.engine.base.Engine.0x...00d0
SELECT orders.id AS orders_id, orders.customer AS orders_customer
FROM orders
WHERE orders.id = :param_1
2010-01-14 03:31:01,808 INFO sqlalchemy.engine.base.Engine.0x...00d0
{'param_1': '55'}
2010-01-14 03:31:01,810 INFO sqlalchemy.engine.base.Engine.0x...00d0
SELECT orderdetails.orderid AS orderdetails_orderid, orderdetails.line
AS orderdetails_line, orderdetails.product AS orderdetails_product,
orderdetails.qtyordered AS orderdetails_qtyordered
FROM orderdetails
WHERE orderdetails.orderid = :param_1 AND orderdetails.line = :param_2
2010-01-14 03:31:01,811 INFO sqlalchemy.engine.base.Engine.0x...00d0
{'param_1': '55', 'param_2': 2}
2010-01-14 03:31:01,883 INFO sqlalchemy.engine.base.Engine.0x...00d0
SELECT orderdetails.orderid AS orderdetails_orderid, orderdetails.line
AS orderdetails_line, orderdetails.product AS orderdetails_product,
orderdetails.qtyordered AS orderdetails_qtyordered
FROM orderdetails
WHERE orderdetails.orderid = :param_1 AND orderdetails.line = :param_2
2010-01-14 03:31:01,884 INFO sqlalchemy.engine.base.Engine.0x...00d0
{'param_1': '55', 'param_2': 3}
2010-01-14 03:31:01,885 INFO sqlalchemy.engine.base.Engine.0x...00d0
SELECT orderdetails.orderid AS orderdetails_orderid, orderdetails.line
AS orderdetails_line, orderdetails.product AS orderdetails_product,
orderdetails.qtyordered AS orderdetails_qtyordered
FROM orderdetails
WHERE :param_1 = orderdetails.orderid
2010-01-14 03:31:01,886 INFO sqlalchemy.engine.base.Engine.0x...00d0
{'param_1': '55'}
>>>
>>>
>>> session.commit()
2010-01-14 03:31:13,245 INFO sqlalchemy.engine.base.Engine.0x...00d0
ROLLBACK
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/session.py", line 671, in
commit
self.transaction.commit()
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/session.py", line 378, in
commit
self._prepare_impl()
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/session.py", line 362, in
_prepare_impl
self.session.flush()
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/session.py", line 1354, in
flush
self._flush(objects)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/session.py", line 1432, in
_flush
flush_context.execute()
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/unitofwork.py", line 261, in
execute
UOWExecutor().execute(self, tasks)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/unitofwork.py", line 753, in
execute
self.execute_save_steps(trans, task)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/unitofwork.py", line 774, in
execute_save_steps
self.execute_dependencies(trans, task)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/unitofwork.py", line 783, in
execute_dependencies
self.execute_dependency(trans, dep, False)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/unitofwork.py", line 765, in
execute_dependency
dep.execute(trans, isdelete)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/unitofwork.py", line 732, in
execute
delete=delete)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/dependency.py", line 369, in
process_dependencies
self._synchronize(state, child, None, False, uowcommit)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/dependency.py", line 411, in
_synchronize
sync.clear(state, self.parent, self.prop.synchronize_pairs)
File "/home/rarch/trunk/sa057/lib/python2.6/site-packages/
SQLAlchemy-0.5.7-py2.6.egg/sqlalchemy/orm/sync.py", line 28, in clear
raise AssertionError("Dependency rule tried to blank-out primary
key column '%s' on instance '%s'" % (r, mapperutil.state_str(dest)))
AssertionError: Dependency rule tried to blank-out primary key column
'orderdetails.orderid' on instance '<OrderDetail at 0x1a757a90>'
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to [email protected].
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.
