seems like. this would be handy to have as a trac ticket, if you have time to create one.
On Aug 17, 2006, at 5:58 PM, Daniel Miller wrote: > I'm writing a GUI app that uses SA sessions extensively to save/ > update/delete graphs of persistent objects. The session usually > does a pretty good job of figuring out what SQL needs to be > executed to persist the entire object graph on session.flush(). > However, I'm having problems with creating and then deleting the > same object (and its children) within a session. Here's a short > example that demonstrates the problem: > > > 01 mapper(Address, addresses) > 02 mapper(User, users, properties=dict( > 03 addresses=relation(Address, > 04 cascade="all,delete-orphan", > 05 backref="user" > 06 ) > 07 )) > 08 s = create_session() > 09 10 u = User() > 11 s.save(u) > 12 13 a = Address() > 14 u.addresses.append(a) > 15 16 # later before session is flushed > 17 u.addresses.remove(a) > 18 19 # and even later the user is deleted > 20 s.delete(u) > 21 22 s.flush() # finally persist pending changes > 23 # this (erroneously) causes "a" to be persisted > 23 # even though it was never saved in the session > > > This is a minimal example to demonstrate the problem. In actuality > the end-user will be adding lots of new Users and Addresses > (fictional entities used for this example only) some of which will > be saved and others will be "deleted" before they ever get the > chance to become persistent. The problem I am having is a side > affect of the fact that the new Address (a) is registered as "new" > in the session when it is appended to u.addresses (line 14), but it > is not unregistered when it is removed from u.addresses (line 17). > > I think that's a bug. A test case is also attached. > > ~ Daniel > from testbase import AssertMixin > import testbase > import unittest, sys, datetime > > import tables > from tables import * > > db = testbase.db > from sqlalchemy import * > > > class SessionTest(AssertMixin): > > def setUpAll(self): > db.echo = False > tables.create() > tables.data() > db.echo = testbase.echo > def tearDownAll(self): > db.echo = False > tables.drop() > db.echo = testbase.echo > def tearDown(self): > clear_mappers() > def setUp(self): > pass > > def test_delete_new_object(self): > mapper(Address, addresses) > mapper(User, users, properties=dict( > addresses=relation(Address, cascade="all,delete- > orphan", backref="user") > )) > s = create_session() > > u = User() > s.save(u) > a = Address() > assert a not in s.new > u.addresses.append(a) > #assert a not in s.new # fails > u.addresses.remove(a) > #assert a not in s.new # fails > s.delete(u) > s.flush() # (erroneously) causes "a" to be persisted > assert u.user_id is None, "Error: user should not be > persistent" > assert a.address_id is None, "Error: address should not be > persistent" > > """ > Suggested behavior: > instead of immediately registering objects that are added > to a collection > as "new", the registration should be deferred until the > session is flushed. > On session.flush() any object "u" with a non-persistent > child "a" and a > cascading save rule will cause "a" to be persisted at that > time. > """ > > > if __name__ == "__main__": > testbase.main() > ---------------------------------------------------------------------- > --- > Using Tomcat but need to do more? Need to support web services, > security? > Get stuff done quickly with pre-integrated technology to make your > job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache > Geronimo > http://sel.as-us.falkag.net/sel? > cmd=lnk&kid=120709&bid=263057&dat=121642______________________________ > _________________ > Sqlalchemy-users mailing list > Sqlalchemy-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Sqlalchemy-users mailing list Sqlalchemy-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users
