[sqlalchemy] odict for mapper properties?
Hi Mike, I see in r6413, that you use an ordered dictionary instead of a standard one for properties, in an attempt to fix some jython ordering annoyingness. Is this really necessary to be compliant with Jython? Would you care to explain? I'm quite puzzled as to how that change could have any effect... Thanks in advance, -- Gaëtan de Menten http://openhex.org --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: odict for mapper properties?
Gaetan de Menten wrote: Hi Mike, I see in r6413, that you use an ordered dictionary instead of a standard one for properties, in an attempt to fix some jython ordering annoyingness. Is this really necessary to be compliant with Jython? Would you care to explain? I'm quite puzzled as to how that change could have any effect... that particular odict is only within the context of a particular unit test which is looking for an exact SQL statement to be rendered based on that mapper. the depending on the order of the address and orders attribute (if i recall correctly the names), its the difference between: select address.foo, address.bar, orders.foo, orders.bar, ... and select orders.foo, orders.bar, address.foo, address.bar, ... i.e. it doesn't make any difference except for a test that is testing for an exact SQL string. dictionary ordering changes based on platform and implementation. In this case those two attributes got reversed when run on Jython. the mapper's internal dictionary of properties is ordered in any case, in this case its just the dictionary used to pass the argument in within the test. Thanks in advance, -- Gaëtan de Menten http://openhex.org --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] License of the example files
Greetings Alchemists, I plan to base a chunk of my code on one of the examples in sqlalchemy/examples. I just want to make sure that those are free to use. SQLAlchemy is licenced under the X11 (MIT) license. Is it also the case for the examples? -- Yannick Gingras http://ygingras.net http://confoo.ca -- track coordinator http://montrealpython.org -- lead organizer signature.asc Description: This is a digitally signed message part.
[sqlalchemy] Re: License of the example files
Yannick Gingras wrote: Greetings Alchemists, I plan to base a chunk of my code on one of the examples in sqlalchemy/examples. I just want to make sure that those are free to use. SQLAlchemy is licenced under the X11 (MIT) license. Is it also the case for the examples? it is ! tell Bill Gates I said hi. -- Yannick Gingras http://ygingras.net http://confoo.ca -- track coordinator http://montrealpython.org -- lead organizer --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: odict for mapper properties?
On Mon, Oct 19, 2009 at 16:04, Michael Bayer mike...@zzzcomputing.com wrote: I see in r6413, that you use an ordered dictionary instead of a standard one for properties, in an attempt to fix some jython ordering annoyingness. Is this really necessary to be compliant with Jython? Would you care to explain? I'm quite puzzled as to how that change could have any effect... i.e. it doesn't make any difference except for a test that is testing for an exact SQL string. Doh! Should have looked at the test in question, that'd have been obvious. Sorry about this. -- Gaëtan de Menten http://openhex.org --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: invalid transaction rollback etc and making a join join
I removed SQLSoup and the caching/stale results issues are gone now. Have to wait a little longer to see if there is any bearing on the MySQL has gone away/invalid transaction thing. Changing the default beaker timeout to something small, like 15 secs, doesn't seem to fix things. Thanks for all the help everyone. On Sat, Oct 17, 2009 at 8:08 PM, cd34 mcd...@gmail.com wrote: On Oct 17, 6:49 pm, Jeff Cook cookieca...@gmail.com wrote: Unfortunately, from a support-seeker point of view, such rhetoric is often necessary. How many times have you written a mailing list or hit sqlalchemy.pool_recycle = 10 I had odd issues -- even though mysql was set to | interactive_timeout | 60 | | net_read_timeout | 30 | | net_write_timeout | 60 | | slave_net_timeout | 3600 | | table_lock_wait_timeout | 50 | | wait_timeout | 60 | A request that was valid and executed once before had problems when pool_recycle was = 30 with pylons. In project/model/meta.py I set Session = scoped_session(sessionmaker(autocommit=True)) which eliminated the situation where the transaction error required restarting paster. Setting this is a bad thing, but then you can see if the issue is within the sql and your translation to sqlalchemy, or, whether it is something external. This prevents the inevitable pylons 'hangup' when you get the sqlalchemy error reported in pylons and have to restart the server to continue debugging. As for caching, you might doublecheck your beaker settings to turn it off while testing. I haven't seen pylons excessively cache with their default site template. --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Sessions, threads, TurboGears best practice?
Hi, I'm hoping someone can help me with properly configuring a session/ transactions for multiple uses as I haven't been able to get it quite right. I've created a python module to contain my model classes and a connection class. This module wil be imported by both single-use scripts (run, then quit), long-running background scripts (run passively while waiting for a new event), and imported into a TurboGears app. I'm using PostgreSQL 8.4, SQLAlchemy 0.5.5, and TurboGears 2.0. After getting different types of transaction errors, e.g. InternalError: (InternalError) current transaction is aborted, commands ignored until end of transaction block InvalidRequestError: Can't reconnect until invalid transaction is rolled back A transaction is already begun. Use subtransactions=True sqlalchemy.exc.InvalidRequestError: A transaction is already begun. Use subtransactions=True to allow subtransactions. I settled on this in my db connection module, which is called by all my scripts: class MyDatabase: def __init__(self, database_connection_string=None): self.database_connection_string = database_connection_string self.engine = create_engine(self.database_connection_string, echo=False) self.metadata = MetaData() self.metadata.bind = self.engine try: db # singleton except NameError: db = MyDatabase() engine = db.engine metadata = db.metadata Session = scoped_session(sessionmaker(bind=engine, autocommit=True, autoflush=False)) Then in each script I import this module, create a new session: session = Session() and query like this: if session.autocommit: session.begin() do stuff that modifies the db, i.e. not just select statements session.commit() I was hoping this is fairly bullet-proof, but unfortunately my TurboGears app still hangs (with no error messages) after running for some period of time, though I think it hangs when multiple queries hit the database at the same time. I'm suspecting some kind of deadlock, but that's just a guess. I'm at a loss as to where the problem lies, but I wanted to check with the experts here that I'm using SA appropriately. Any help/suggestions greatly appreciated. Cheers, Demitri --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Synchronization problem at backref of a one-to-many relation to the same class.
Dnia 2009-10-08, czw o godzinie 11:16 -0400, Michael Bayer pisze: Tefnet Developers wrote: Dnia 2009-10-08, czw o godzinie 09:59 -0400, Michael Bayer pisze: Is this a SQLAlchemy bug or my mistake? Backrefs deal with the two-way relation between A-B, but the event does not propagate in most cases to C or beyond, i.e. A-B-C where B is attached to A would indicate C-B becomes detached in memory. After a commit() all those references would be expired and then you'd see the actual connections. Yes, sorry, I had a mistake in my test and in fact the behaviour is consistent. I have just created my own AttributeExtension which handles these situations. Thanks for clarifying things out :). regards, Filip Zyzniewski Tefnet --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] using ORM in AttributeExtension
Hi,
and here comes another problem with my project utilizing SQLAlchemy :).
I am trying to use ORM in AttributeExtension:
(http://dpaste.com/109454/)
=
import sqlalchemy
import sqlalchemy.ext.declarative
Base = sqlalchemy.ext.declarative.declarative_base(mapper =
sqlalchemy.orm.mapper)
engine = sqlalchemy.create_engine('sqlite:///:memory:', echo = False)
session = sqlalchemy.orm.scoped_session(sqlalchemy.orm.sessionmaker(bind
= engine))
Base.metadata.bind = engine
class AttrEx(sqlalchemy.orm.interfaces.AttributeExtension):
def set(self, state, value, oldvalue, initiator):
for o in session.query(Foo):
pass
return value
class Foo(Base):
Id = sqlalchemy.Column( sqlalchemy.types.Integer, primary_key =
True, autoincrement =True)
__tablename__ = 'foo'
class Bar(Base):
Id = sqlalchemy.Column(sqlalchemy.types.Integer, primary_key=True,
autoincrement = True)
someAttr =
sqlalchemy.orm.column_property(sqlalchemy.Column(sqlalchemy.types.Integer),
extension = AttrEx())
__tablename__ = 'bar'
Base.metadata.create_all()
a = Bar()
session.add(a)
a.someAttr = 5
assert a.someAttr == 5
session.commit()
assert a.someAttr == 5
=
Seccond assert explodes. It seems that query'ing in AttrEx's set()
method triggers flush (autoflush which I need) and somehow value
returned by set() gets lost. Is there a correct way to manipulate other
mapped objects in AttributeExtensions?
regards,
Filip Zyznieski
Tefnet
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[sqlalchemy] purpose of class_mapper
What is the purpose of class_mapper? I can't find it in the .4 docs
for the tutorials I'm looking at, yet when I don't call it as
https://svn.enthought.com/svn/enthought/sandbox/EnvisageSQLAlchemy/enthought/sqlalchemy/has_traits_orm.py
notes, I get a
AttributeError:
# 'ColumnProperty' object has no attribute 'key'
Is my setup incorrect that causes me to need class_mapper, while the .
4 docs don't include it? Or am I doing something different enough
from the tutorials to require it?
I'm running
Python: 2.5.1
sqlite: 2.3.2
sqlalchemy 0.4.8
# create the database file and associated tables
statsFile = Path('./stats.db')
engine = create_engine('sqlite:///' + statsFile,
echo=False)
conn = engine.connect()
metadata = MetaData(engine)
self.createStatsTables(metadata)
metadata.create_all(engine) # save tables (up to here
works by looking at the database outside python using the sqlite3
command tool
Session.configure(bind=engine)
session = Session()
class User(object):
self.userName = ''
user = User()
user.userName = 'Joe'
mapper(User, usersTable)
class_mapper(User) # if I don't add this to the
tutorial code, I get the error
session.save(user)
session.commit()
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[sqlalchemy] Re: purpose of class_mapper
strattonbrazil wrote: What is the purpose of class_mapper? I can't find it in the .4 docs for the tutorials I'm looking at, yet when I don't call it as https://svn.enthought.com/svn/enthought/sandbox/EnvisageSQLAlchemy/enthought/sqlalchemy/has_traits_orm.py notes, I get a AttributeError: # 'ColumnProperty' object has no attribute 'key' that is an ancient bug which refers to the fact that mappers have not been compiled, yet an expression is doing something along the lines of User.some_property == somevalue. The Class.descriptor expression approach was new in 0.4 and had some incompleteness. To work around it in 0.4 the most general way is to call compile_mappers(). class_mapper() also has the effect of invoking a compile if the mapper being returned was not yet compiled. class_mapper() in modern SQLAlchemy would normally only be used if additional configuration needs to be added to an existing mapper, given only a class. --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
