On "except DuplicateKeyError:" you need to expunge the object from the session or the autoflusher will still find the object at the end of the request, will see that it's dirty and pending creation (as the previous flush failed) and will try to create it again.
See http://ming.readthedocs.io/en/latest/api/ming.odm.html#ming.odm.odmsession.ODMSession.expunge Most common pattern is just to call ODMSession.clear(), so that all objects are expunged as usually in a well defined api there is nothing you must create/edit if it failed. On Mon, Jan 23, 2017 at 12:58 PM, Giovanni Colucci <[email protected]> wrote: > Hello guys, > > I am using TG 2.3.10 with Ming I started the project using the quickstart > command. > > My TG application is basically a REST web service. I am not really sure > how to handle DuplicationKeyError when adding new items into my DB. > > I thought that catching the DuplicationKeyError from inside my controller > method code was enough, but whenever I try to perform a POST request with > some duplicate data the application crash and return me a 500 HTTP status > code. > > The following is a sample code that fail for me, the sensorID field got a > UniqueIndex into the model definition. > > @expose('json') > @decode_params('json') > @validate({ > "sensorID": validators.String(not_empty=True), > "definition": validators.String(not_empty=True) > }) > @require(in_group('admins')) > def post(self, *args, **kw): > #Check if there was error during the validation process > if request.validation['errors']: > errors = dict([(field, str(e)) for field, e in request. > validation['errors'].items()]) > logger.warning('Unable to add a sensor type due to a > validation error. ' + str(errors)) > response.status = 400 > return dict(errors=errors) > > try: > sensor = model.Sensor( > sensorID=kw['sensorID'], definition=kw['definition'] > ) > #Flush it into the DB > model.DBSession.flush() > response.status = 201 > except DuplicateKeyError: > response.status = 400 > return dict(errors="Sensor already present!") > except: > logger.exception('The sensor type %s was not added due to an > unexpected error.' % kw['sensorTypeID']) > abort(500) > else: > return > > This is the trackback that I see when I try to insert a document that > contain the same sensorID string. > > Traceback (most recent call last): > File "/var/www/backend/envBK/lib/python2.7/site-packages/tg/wsgiapp.py", > line 120, in __call__ > response = self.wrapped_dispatch(controller, environ, context) > File > "/var/www/backend/envBK/lib/python2.7/site-packages/tg/appwrappers/mingflush.py", > line 58, in __call__ > session.flush_all() > File "build/bdist.linux-x86_64/egg/ming/odm/odmsession.py", line 411, > in flush_all > sess.flush() > File "build/bdist.linux-x86_64/egg/ming/odm/base.py", line 27, in inner > result = func(obj, *args, **kwargs) > File "build/bdist.linux-x86_64/egg/ming/odm/odmsession.py", line 99, in > flush > self.uow.flush() > File "build/bdist.linux-x86_64/egg/ming/odm/unit_of_work.py", line 45, > in flush > inow(obj, st) > File "build/bdist.linux-x86_64/egg/ming/odm/base.py", line 27, in inner > result = func(obj, *args, **kwargs) > File "build/bdist.linux-x86_64/egg/ming/odm/odmsession.py", line 111, > in insert_now > mapper(obj).insert(obj, st, self, **kwargs) > File "build/bdist.linux-x86_64/egg/ming/odm/base.py", line 27, in inner > result = func(obj, *args, **kwargs) > File "build/bdist.linux-x86_64/egg/ming/odm/mapper.py", line 71, in > insert > session.impl.insert(doc, validate=False) > File "build/bdist.linux-x86_64/egg/ming/session.py", line 23, in wrapper > return func(self, doc, *args, **kwargs) > File "build/bdist.linux-x86_64/egg/ming/session.py", line 163, in insert > bson = self._impl(doc).insert(data, safe=kwargs.get('safe', True)) > File "build/bdist.linux-x86_64/egg/pymongo/collection.py", line 541, in > insert > _check_write_command_response(results) > File "build/bdist.linux-x86_64/egg/pymongo/helpers.py", line 233, in > _check_write_command_response > raise DuplicateKeyError(error.get("errmsg"), 11000, error) > > Seems like I am missing something but I am a bit confused. Could anyone > help me in this? > > -- > You received this message because you are subscribed to the Google Groups > "TurboGears" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/turbogears. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "TurboGears" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/turbogears. For more options, visit https://groups.google.com/d/optout.
