the important thing is your sqlite version. im on 3.2.1. my
pysqlite seems to be....2.0.2 ? maybe a new pysqlite bug, not sure.
also the sql echo shows that something is weird...its inserting a
row, then deleting it, using id 1, which is what the id should be.
the "rowcount" should definitely be "1" and not "0".
On Jan 11, 2007, at 8:30 PM, Kumar McMillan wrote:
>
> hi. the reason for the flush strangeness is I grabbed these
> statements from separate areas of the app to reproduce the scenario
> (but I guess the app needs cleanup, heh).
>
> What version of pysqilte did you test with? Mine is pysqlite 2.3.2 on
> python 2.4.3, sqlalchemy dev r 2183; maybe that's all it is (memory
> weirdness).
>
> below is my sql, output, etc, showing the same test failing for me.
>
> I see what you mean about the sqlite instances. Actually when I run
> it w/ the 2nd call as a connection to postgres, there are no errors.
> Since that is a better representation of my real problem I'm not so
> worried about the failure anymore. And currently I'm working around
> it all using two separate BoundMetaData which is OK to me. But I'm
> still curious as to what could be wrong with my setup.
>
> _
>
> 2007-01-11 19:16:55,779 INFO sqlalchemy.engine.base.Engine.0x..30
> PRAGMA table_info(offers)
> 2007-01-11 19:16:55,779 INFO sqlalchemy.engine.base.Engine.0x..30 {}
> 2007-01-11 19:16:55,781 INFO sqlalchemy.engine.base.Engine.0x..30
> CREATE TABLE offers (
> id INTEGER NOT NULL,
> name TEXT,
> PRIMARY KEY (id)
> )
>
>
> 2007-01-11 19:16:55,781 INFO sqlalchemy.engine.base.Engine.0x..30 None
> 2007-01-11 19:16:55,782 INFO sqlalchemy.engine.base.Engine.0x..30
> COMMIT
> 2007-01-11 19:16:55,784 INFO sqlalchemy.engine.base.Engine.0x..30
> BEGIN
> 2007-01-11 19:16:55,786 INFO sqlalchemy.engine.base.Engine.0x..30
> INSERT INTO offers (name) VALUES (?)
> 2007-01-11 19:16:55,786 INFO sqlalchemy.engine.base.Engine.0x..30
> ['foobar']
> 2007-01-11 19:16:55,787 INFO sqlalchemy.engine.base.Engine.0x..30
> COMMIT
> 2007-01-11 19:16:55,790 INFO sqlalchemy.engine.base.Engine.0x..30
> SELECT offers.id AS offers_id, offers.name AS offers_name
> FROM offers ORDER BY offers.oid
> 2007-01-11 19:16:55,790 INFO sqlalchemy.engine.base.Engine.0x..30 []
> 2007-01-11 19:16:55,791 INFO sqlalchemy.engine.base.Engine.0x..30
> BEGIN
> 2007-01-11 19:16:55,792 INFO sqlalchemy.engine.base.Engine.0x..30
> DELETE FROM offers WHERE offers.id = ?
> 2007-01-11 19:16:55,793 INFO sqlalchemy.engine.base.Engine.0x..30 [1]
> 2007-01-11 19:16:55,793 INFO sqlalchemy.engine.base.Engine.0x..30
> COMMIT
> 2007-01-11 19:16:55,794 INFO sqlalchemy.engine.base.Engine.0x..30
> SELECT offers.id AS offers_id, offers.name AS offers_name
> FROM offers ORDER BY offers.oid
> 2007-01-11 19:16:55,795 INFO sqlalchemy.engine.base.Engine.0x..30 []
> 2007-01-11 19:16:55,796 INFO sqlalchemy.engine.base.Engine.0x..30
> PRAGMA table_info(offers)
> 2007-01-11 19:16:55,796 INFO sqlalchemy.engine.base.Engine.0x..30 {}
> 2007-01-11 19:16:55,796 INFO sqlalchemy.engine.base.Engine.0x..30
> DROP TABLE offers
> 2007-01-11 19:16:55,797 INFO sqlalchemy.engine.base.Engine.0x..30 None
> 2007-01-11 19:16:55,797 INFO sqlalchemy.engine.base.Engine.0x..30
> COMMIT
> 2007-01-11 19:16:55,799 INFO sqlalchemy.engine.base.Engine.0x..30
> PRAGMA table_info(offers)
> 2007-01-11 19:16:55,799 INFO sqlalchemy.engine.base.Engine.0x..30 {}
> 2007-01-11 19:16:55,800 INFO sqlalchemy.engine.base.Engine.0x..30
> CREATE TABLE offers (
> id INTEGER NOT NULL,
> name TEXT,
> PRIMARY KEY (id)
> )
>
>
> 2007-01-11 19:16:55,800 INFO sqlalchemy.engine.base.Engine.0x..30 None
> 2007-01-11 19:16:55,800 INFO sqlalchemy.engine.base.Engine.0x..30
> COMMIT
> 2007-01-11 19:16:55,802 INFO sqlalchemy.engine.base.Engine.0x..30
> BEGIN
> 2007-01-11 19:16:55,803 INFO sqlalchemy.engine.base.Engine.0x..30
> INSERT INTO offers (name) VALUES (?)
> 2007-01-11 19:16:55,803 INFO sqlalchemy.engine.base.Engine.0x..30
> ['foobar']
> 2007-01-11 19:16:55,804 INFO sqlalchemy.engine.base.Engine.0x..30
> COMMIT
> 2007-01-11 19:16:55,805 INFO sqlalchemy.engine.base.Engine.0x..30
> SELECT offers.id AS offers_id, offers.name AS offers_name
> FROM offers ORDER BY offers.oid
> 2007-01-11 19:16:55,805 INFO sqlalchemy.engine.base.Engine.0x..30 []
> 2007-01-11 19:16:55,806 INFO sqlalchemy.engine.base.Engine.0x..30
> BEGIN
> 2007-01-11 19:16:55,807 INFO sqlalchemy.engine.base.Engine.0x..30
> DELETE FROM offers WHERE offers.id = ?
> 2007-01-11 19:16:55,807 INFO sqlalchemy.engine.base.Engine.0x..30 [1]
> 2007-01-11 19:16:55,808 INFO sqlalchemy.engine.base.Engine.0x..30
> ROLLBACK
> Traceback (most recent call last):
> File "test_sa_concurrent.py", line 56, in ?
> db_roundtrip('sqlite:///:memory:')
> File "test_sa_concurrent.py", line 42, in db_roundtrip
> session.flush()
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/session.py",
> line 220, in flush
> self.uow.flush(self, objects)
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/unitofwork.py",
> line 194, in flush
> flush_context.execute()
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/unitofwork.py",
> line 333, in execute
> head.execute(self)
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/unitofwork.py",
> line 470, in execute
> UOWExecutor().execute(trans, self)
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/unitofwork.py",
> line 795, in execute
> self.execute_delete_steps(trans, task)
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/unitofwork.py",
> line 824, in execute_delete_steps
> self.delete_objects(trans, task)
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/unitofwork.py",
> line 801, in delete_objects
> task._delete_objects(trans)
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/unitofwork.py",
> line 464, in _delete_objects
> task.mapper.delete_obj(task.todelete_objects, trans)
> File "/Users/kumar/src/sqlalchemy/lib/sqlalchemy/orm/mapper.py",
> line 1070, in delete_obj
> raise exceptions.ConcurrentModificationError("Updated rowcount %d
> does not match number of objects updated %d" % (c.cursor.rowcount,
> len(delete)))sqlalchemy.exceptions.ConcurrentModificationError:
> Updated rowcount 0 does not match number of objects updated 1
>
>
> On 1/6/07, Michael Bayer <[EMAIL PROTECTED]> wrote:
>>
>> when i run this program, I get no errors.
>>
>> a few things to note:
>>
>> it makes no sense to do a session.flush() after youve dropped the
>> table (similarly, it makes no sense to flush() before youve done
>> anything but thats less of an issue). if there were any modified
>> state within your session to actually be flushed, the operation would
>> fail since the table is dropped (but in this test, theres no changes
>> to flush at that point, so no error occurs).
>>
>> running the same test twice with two separate instances of "sqlite://
>> memory" will produce no continuity between the two databases, since
>> sqlite://memory databases are completely unique per connection. but
>> again, in this test youre doing a completely new and unrelated set of
>> operations on each connection, so no error occurs.
>>
>> wild guess, that the test you have which fails is switching between
>> "sqlite://memory" databases within a single ORM session, so the
>> update of a row saved within the first sqlite://memory database
>> produces no changes within the second sqlite://memory database since
>> its a completely new database (but then, youd also have to get the
>> table creates in there too, so still not exactly sure what the
>> conditions are on your end).
>>
>> in any case, viewing SQL output should reveal exactly whats going on.
>>
>>
>> On Jan 6, 2007, at 6:54 PM, Kumar McMillan wrote:
>>
>>> hello.
>>>
>>> I'm trying to use DynamicMetaData so that two separate tests can
>>> each
>>> connect to a unique db, create some tables, insert some data, delete
>>> that data, then drop the tables.
>>>
>>> This seems to yield ...
>>>
>>> sqlalchemy.exceptions.ConcurrentModificationError: Updated
>>> rowcount 0
>>> does not match number of objects updated 1
>>>
>>> ... the second time around, when trying to delete the data. I
>>> checked
>>> the list and FAQ and note that I am *not* trying to modify a primary
>>> key. This seems related to the use of DynamicMetaData and the fact
>>> that I am creating the table then dropping it.
>>>
>>> I was able to reproduce this scenario in a single test (below and
>>> attached) so maybe you can see something simple I'm doing wrong?
>>> Experimenting, I noticed that if I use two separate BoundMetaData
>>> instances *or* switch to checkfirst=True and not drop the table then
>>> the test works fine. However, I don't see why this shouldn't be
>>> possible with DynamicMetaData. Thanks in advance.
>>>
>>> PS. this was in sqlalchemy trunk r 2183
>>>
>>> _
>>>
>>> import sqlalchemy
>>> from sqlalchemy import *
>>> from sqlalchemy.ext.assignmapper import assign_mapper
>>> from sqlalchemy.ext.sessioncontext import SessionContext
>>> def eq_(a,b):
>>> assert a==b, "%s != %s" % (a,b)
>>>
>>> meta = DynamicMetaData()
>>>
>>> offers = Table("offers", meta,
>>> Column("id", INT, primary_key=True),
>>> Column("name", String ),
>>> )
>>> class Offer(object):
>>> pass
>>>
>>> def db_roundtrip(dsn):
>>> conn = meta.connect(dsn)
>>> meta.engine.echo = 1
>>>
>>> context = SessionContext(
>>> lambda: sqlalchemy.create_session(bind_to=meta.engine))
>>> assign_mapper(context, Offer, offers)
>>> session = context.current
>>>
>>> meta.create_all()
>>> session.flush()
>>>
>>> offer = Offer()
>>> offer.name = 'foobar'
>>> session.save(offer)
>>> session.flush()
>>>
>>> rows = Offer.select()
>>> eq_(len(rows), 1)
>>> eq_(rows[0].id, 1)
>>> eq_(rows[0].name, 'foobar')
>>>
>>> session.delete(offer)
>>> session.flush()
>>>
>>> rows = Offer.select()
>>> eq_(len(rows), 0)
>>>
>>> meta.drop_all()
>>> session.flush()
>>>
>>> sqlalchemy.orm.clear_mappers()
>>>
>>> if __name__ == '__main__':
>>>
>>> db_roundtrip('sqlite:///:memory:')
>>> # pretend this is another connection :
>>> db_roundtrip('sqlite:///:memory:')
>>>
>>> print 'OK'
>>>
>>>>
>>> <test_sa_concurrent.py>
>>
>>
>>>
>>
>
> >
--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---
