Re: [sqlalchemy] object has no attribute 'delete'
Hi, You can try: My.query.filter_by(id=id).delete() (If your object can use the .query syntax) or session.query(My).filter_by(id=id).delete() On Apr 13, 2010 6:12 AM, jo jose.soa...@sferacarta.com wrote: Hi all, I'm trying migrate from 0.3 to 0.6 I don't know how to delete an object in the old version it was: My.get(1).delete() in 0.6: My.get(1).delete() AttributeError: 'My' object has no attribute 'delete' j -- Jose Soares Sferacarta Net Via Bazzanese 69 40033 Casalecchio di Reno Bologna - Italy Ph +39051591054 fax +390516131537 web:www.sferacarta.com Le informazioni contenute nella presente mail ed in ogni eventuale file allegato sono riservate e, comunque, destinate esclusivamente alla persona o ente sopraindicati, ai sensi del decreto legislativo 30 giugno 2003, n. 196. La diffusione, distribuzione e/o copiatura della mail trasmessa, da parte di qualsiasi soggetto diverso dal destinatario, sono vietate. La correttezza, l’integrità e la sicurezza della presente mail non possono essere garantite. Se avete ricevuto questa mail per errore, Vi preghiamo di contattarci immediatamente e di eliminarla. Grazie. This communication is intended only for use by the addressee, pursuant to legislative decree 30 June 2003, n. 196. It may contain confidential or privileged information. You should not copy or use it to disclose its contents to any other person. Transmission cannot be guaranteed to be error-free, complete and secure. If you are not the intended recipient and receive this communication unintentionally, please inform us immediately and then delete this message from your system. Thank you. -- 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.comsqlalchemy%2bunsubscr...@googlegroups.com . For more options, visit this group at http://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.
[sqlalchemy] 'NoneType' object has no attribute '_sa_iterator' exception
Hi all! I'm running SQLAlchemy 0.6b2 for a while and i've seem some strange exception (AttributeError: 'NoneType' object has no attribute '_sa_iterator') happening one in a while. This is my stacktrace: Traceback (most recent call last): File /usr/lib/python2.5/threading.py, line 486, in __bootstrap_inner self.run() File /usr/lib/python2.5/threading.py, line 446, in run self.__target(*self.__args, **self.__kwargs) File ./db/models/job.py, line 109, in run func(self) File ./queue/queue.py, line 284, in job_finished job = session.merge(job) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/session.py, line 1126, in merge load=load, _recursive=_recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/session.py, line 1188, in _merge prop.merge(self, state, state_dict, merged_state, merged_dict, load, _recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/properties.py, line 681, in merge obj = session._merge(current_state, current_dict, load=load, _recursive=_recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/session.py, line 1188, in _merge prop.merge(self, state, state_dict, merged_state, merged_dict, load, _recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/properties.py, line 661, in merge for current in instances: File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/collections.py, line 570, in __iter__ return iter(getattr(self._data(), '_sa_iterator')()) AttributeError: 'NoneType' object has no attribute '_sa_iterator' I don't have a good test for this, but i'm trying to create one. Does anyone knows why this is happening? Thanks! -- Fernando Takai -- 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.
Re: [sqlalchemy] 'NoneType' object has no attribute '_sa_iterator' exception
is it possible your object is present in a session that is, in a different thread, being expired as this operation runs ? I don't know, but i can verify that. If that is happening, what can i do to prevent? Well seems like the project you want to access is just None. SA can't do anything with it. I had a similar problem recently, it was… I'm not trying to access anything, i'm just trying to merge the object into the session… On Sat, Mar 27, 2010 at 3:25 PM, Michael Bayer mike...@zzzcomputing.com wrote: On Mar 27, 2010, at 12:42 PM, Fernando Takai wrote: Hi all! I'm running SQLAlchemy 0.6b2 for a while and i've seem some strange exception (AttributeError: 'NoneType' object has no attribute '_sa_iterator') happening one in a while. This is my stacktrace: Traceback (most recent call last): File /usr/lib/python2.5/threading.py, line 486, in __bootstrap_inner self.run() File /usr/lib/python2.5/threading.py, line 446, in run self.__target(*self.__args, **self.__kwargs) File ./db/models/job.py, line 109, in run func(self) File ./queue/queue.py, line 284, in job_finished job = session.merge(job) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/session.py, line 1126, in merge load=load, _recursive=_recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/session.py, line 1188, in _merge prop.merge(self, state, state_dict, merged_state, merged_dict, load, _recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/properties.py, line 681, in merge obj = session._merge(current_state, current_dict, load=load, _recursive=_recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/session.py, line 1188, in _merge prop.merge(self, state, state_dict, merged_state, merged_dict, load, _recursive) File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/properties.py, line 661, in merge for current in instances: File /usr/lib/python2.5/site-packages/SQLAlchemy-0.6beta2-py2.5-linux-x86_64.egg/sqlalchemy/orm/collections.py, line 570, in __iter__ return iter(getattr(self._data(), '_sa_iterator')()) AttributeError: 'NoneType' object has no attribute '_sa_iterator' is it possible your object is present in a session that is, in a different thread, being expired as this operation runs ? I don't have a good test for this, but i'm trying to create one. Does anyone knows why this is happening? Thanks! -- Fernando Takai -- 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. -- 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. -- Fernando Takai -- 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.
Re: [sqlalchemy] Re: SQLAlchemy, Twisted, and sAsync
Hi!, I'm using SQLAlchemy on a heavily threaded env - something like 30~40 threads working with SQLAlchemy objects. What you need to watchout is: * Eager load objects - getting nasty lazyload exceptions is not funny * Take off the objects from the session and, if you need to use them later, merge to the current thread session - i did this because i had some object-is-already-on-session-foobar exception * Don't forget to use scoped_session Beside those two points, working with threaded apps is quite easy with SQLAlchemy. :) On Fri, Mar 26, 2010 at 10:12 AM, Matthew Williams mgwilli...@gmail.com wrote: Thank you, Simon, for clarifying this and pointing out that part of the SQLAlchemy docs... somehow I missed that part :-). On Mar 26, 2010, at 7:30 AM, King Simon-NFHD78 wrote: I think that point should be clarified, so that people don't later come across this post and just accept it without understanding. I imagine that SQLALchemy is used in a lot of threaded applications. For example, it is the recommended ORM in web frameworks such as Pylons and TurboGears, which work fine in threaded environments. However, typically in these libraries a web request is handled by a single thread, and all the SQLAlchemy operations occur within the scope of that request. As long as you don't share a Session instance between the threads, you won't have any problems. SQLAlchemy provides a ScopedSession class which helps in these situations, as you can call the constructor many times on a single thread and always get the session instance back for that thread. Sessions themselves aren't thread-safe. When an instance is loaded from the database, it is linked to the session that loaded it. This means that when you have lazy-loading properties on that instance (such as related classes, or deferred column properties), they will be automatically loaded when they are accessed, in the same session. This will cause a problem if you load an instance in thread A, hand the object off to thread B, and then thread B accesses one of these lazy-loading properties. The load will occur in thread A's session, which might be in the middle of doing something else. The solution to this is either to eager-load all the attributes you think you are going to need before handing the instance off to another thread (difficult), or (probably better) to detach (expunge) the instance from thread A's session. Thread B should then merge the object into its own session (using the load=False flag so that it doesn't needlessly requery the database). The Session docs at http://www.sqlalchemy.org/docs/session.html explain the lifecycle of loaded instances. I haven't actually done any of this - I've only ever used SA from TG and command-line scripts, but I think the principles are about right. I hope that helps, Simon -- 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. -- Fernando Takai -- 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.
Re: [sqlalchemy] Re: UnboundExecutionError with object on session
This is the exact code that is running now: log.info(Creating proxies for file %s % job.file) job = session.merge(job) if agent.transcoder.run(job.local_filename): log.info(Transcoding finished for file %s % job.local_filename) else: log.error(Occurred a problem while transcoding the file. Please, verify the logs.) job.error_status = Occurred a problem while transcoding the file. Please, verify the logs. (The problem is occurring on the log.info line) As you can see, i *am* merging the job on the current session - so, the exception shouldn't be happening. Also, i use the local_filename variable before, so it's not expired (afaik). On Nov 17, 2009, at 1:35 PM, Michael Bayer wrote: Fernando Takai wrote: I have changed my code to be like this: job = session.merge(job) # Merge docs says that object does not get into the session session.add(job) log.info(Job finished! %s % job.file) When using latest SQLAlchemy trunk and 0.5.6 sometimes i get UnboundExecutionError. Also, i can assure that all my attributes are loaded - i use all of them before and no error occurs. but they may be expired at some point. If their host session is rolled back or committed, for example. The stack trace will illustrate exactly what action is initiating the load operation. For example, in the stack trace you posted, the job.local_filename attribute is unloaded or expired. You can test for this by seeing that local_filename is not present in job.__dict__. Maybe there's something wrong with the way i'm getting the session: session = Session.object_session(job) if not session: session = Session() there's nothing wrong with it per se except it appears to be guessing as to what session should be used - well lets see if this object has a session from somewhere, or otherwise we'll just make one, maybe not. Sessions can be created as much as you like but they work best when they are in charge of their scope, i.e.: def do_something(): # build the one session we care about for this thread/operation sess = session() # ensure everyone from outside is merged into our one session o1 = sess.merge(o1) o2 = sess.merge(o2) o3 = sess.merge(o3) # commit with authority sess.commit() as opposed to: def do_something(): s1 = object_session(o1) or Session() s2 = object_session(o2) or Session() s3 = object_session(o3) or Session() s3.commit() s2.commit() ? or no ? where did this session come from ? --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~--- -- Fernando Takai http://twitter.com/fernando_takai -- 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.
[sqlalchemy] Re: UnboundExecutionError with object on session
I have changed my code to be like this: job = session.merge(job) # Merge docs says that object does not get into the session session.add(job) log.info(Job finished! %s % job.file) When using latest SQLAlchemy trunk and 0.5.6 sometimes i get UnboundExecutionError. Also, i can assure that all my attributes are loaded - i use all of them before and no error occurs. Maybe there's something wrong with the way i'm getting the session: session = Session.object_session(job) if not session: session = Session() On Nov 16, 2009, at 3:27 PM, Michael Bayer wrote: Fernando Takai wrote: Hi all! I've experiencing this problem for some time now and even after debugging, i could not find why it happens. I have a medium sized multi-thread application that manipulates SQLAlchemy objects - the objects are passed from thread to thread, so, when i load an instance i close the session. After working on the object, i need to update the status of the it, so i do something like this: job.status = FINISHED session.add(job) log.info(Finished job %s % job.filename) session.flush() This code works pretty well, but from time to time, i get this on the logs: UnboundExecutionError: Instance Job at 0x413ee50 is not bound to a Session; attribute refresh operation cannot proceed The complete stacktrace is here: http://pastebin.org/54196 Could this be happening because of my pool_recycle setting (300 seconds) ? its not related to the pool. Your objects have expired or unloaded attributes present on them which will attempt to load when accessed. The object must be attached to a Session for this to proceed. the easiest way to deal with this is to merge() the objects into a new thread-local Session before using. Alternatively, ensure all required attributes are loaded. This often requires touching the attributes explicitly in the case of joined table inheritance or lazily-loaded relations(). Also note that calling session.commit() or session.rollback() expires all attributes, so avoid these in the case of objects becoming detached, or expunge() the objects before an expiration occurs. -- Fernando Takai http://twitter.com/fernando_takai --~--~-~--~~~---~--~~ 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] UnboundExecutionError with object on session
Hi all! I've experiencing this problem for some time now and even after debugging, i could not find why it happens. I have a medium sized multi-thread application that manipulates SQLAlchemy objects - the objects are passed from thread to thread, so, when i load an instance i close the session. After working on the object, i need to update the status of the it, so i do something like this: job.status = FINISHED session.add(job) log.info(Finished job %s % job.filename) session.flush() This code works pretty well, but from time to time, i get this on the logs: UnboundExecutionError: Instance Job at 0x413ee50 is not bound to a Session; attribute refresh operation cannot proceed The complete stacktrace is here: http://pastebin.org/54196 Could this be happening because of my pool_recycle setting (300 seconds) ? --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
