I see that it is not happened when "bind" passed directly to "sessionmaker"
сб, 21 окт. 2017 г. в 18:33, Антонио Антуан <a.ch....@gmail.com>: > > > пятница, 20 октября 2017 г., 20:50:52 UTC+3 пользователь Mike Bayer > написал: > >> On Fri, Oct 20, 2017 at 11:05 AM, Simon King <si...@simonking.org.uk> >> wrote: >> > The "is not None" is important when checking a variable that may >> > contain a ClauseElement, precisely because ClauseElement defines that >> > __bool__ method. >> > >> > However, in Session.get_bind(), "mapper" is not supposed to contain a >> > ClauseElement. It should either be an instance of >> > sqlalchemy.orm.mapper.Mapper, or None, in which case "if mapper:" is a >> > valid and concise way to write it. Comparing to None might be strictly >> > more accurate, but it shouldn't be necessary. >> >> agree, "mapper" means "mapper" and it is not supposed to be a >> ClauseElement. This sounds like arguments are not being passed >> correctly somewhere. Would need a demonstration script if something >> in SQLAlchemy itself is claimed to be making the mistake. >> > > Ok, that code produces mentioned error: > https://gist.github.com/aCLr/113ac292c05bdb01e964d8e9884d6e5f > Traceback (most recent call last): > File "/home/anton/Projects/proj/core/run/stuff.py", line 100, in <module> > Session.query(with_recursive).set_shard('default').all() > File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/query.py", line 2654, > in all > File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/query.py", line 2802, > in __iter__ > File "/home/anton/Projects/proj/core/run/stuff.py", line 28, in > _execute_and_instances > shard_id=self._shard_id).execute( > File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/query.py", line 2806, > in _connection_from_session > File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/session.py", line 984, > in connection > File "/home/anton/Projects/proj/core/run/stuff.py", line 40, in get_bind > original_bind = super(RoutingSession, self).get_bind(mapper, clause) > File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/session.py", line > 1336, in get_bind > File "build/bdist.linux-x86_64/egg/sqlalchemy/sql/elements.py", line > 539, in __bool__ > TypeError: Boolean value of this clause is not defined > > >> > >> > Simon >> > > >> > >> > >> > On Fri, Oct 20, 2017 at 3:17 PM, Антонио Антуан <a.ch...@gmail.com> >> wrote: >> >> Really, `mapper` contains this: <sqlalchemy.sql.selectable.CTE at >> >> 0x7fe673fb0a50; group_getter>. But does it changes something? I >> already >> >> encountered this problem in my code, when I checked sqla-objects >> existance >> >> without "is not None", project was broken. Is it normal to omit that >> >> condition in sqlalchemy code? >> >> >> >> I use: >> >>>>> sqlalchemy.__version__ >> >> '1.0.19' >> >> >> >> пятница, 20 октября 2017 г., 16:42:23 UTC+3 пользователь Simon King >> написал: >> >>> >> >>> On Fri, Oct 20, 2017 at 2:15 PM, Антонио Антуан <a.ch...@gmail.com> >> wrote: >> >>> > Hi. >> >>> > I use my own `RoutingSession` and `RoutingQuery` implementation, >> most of >> >>> > it >> >>> > inspired by `sqlalchemy.ext.horizontal_shard`: >> >>> > >> >>> > class RoutingSession(Session): >> >>> > def get_bind(self, mapper=None, clause=None, shard_id=None, >> >>> > **kwargs): >> >>> > original_bind = None >> >>> > try: >> >>> > original_bind = super(RoutingSession, >> self).get_bind(mapper, >> >>> > clause) >> >>> > except UnboundExecutionError: >> >>> > # may not be bound >> >>> > pass >> >>> > if shard_id is None: >> >>> > shard_id = TenantIDStorage.get_shard_id() # just >> global >> >>> > storage >> >>> > bind_for_shard = self.__binds[shard_id] >> >>> > if original_bind is not None and original_bind.url == >> >>> > bind_for_shard.url: >> >>> > return original_bind >> >>> > else: >> >>> > return bind_for_shard >> >>> > >> >>> > def __init__(self, shards=None, query_cls=CachingQuery, >> >>> > engines_factory=None, **kwargs): >> >>> > super(RoutingSession, self).__init__(query_cls=query_cls, >> >>> > **kwargs) >> >>> > self.__binds = {} >> >>> > self.engines_factory = engines_factory >> >>> > if shards is not None: >> >>> > self.update_shards(**shards) >> >>> > >> >>> > def _add_bind(self, key, bind): >> >>> > self.__binds[key] = bind >> >>> > >> >>> > >> >>> > >> >>> > >> >>> > class RoutingQuery(Query): >> >>> > def __init__(self, *args, **kwargs): >> >>> > super(RoutingQuery, self).__init__(*args, **kwargs) >> >>> > self._shard_id = TenantIDStorage.get_shard_id() >> >>> > >> >>> > def get(self, ident): >> >>> > self._check_bound_to_shard() >> >>> > return super(CachingQuery, self).get(ident) >> >>> > >> >>> > def _check_bound_to_shard(self): >> >>> > if self._shard_id is None: >> >>> > raise ValueError('query not bound to any shard') >> >>> > >> >>> > def _execute_and_instances(self, querycontext): >> >>> > self._check_bound_to_shard() >> >>> > querycontext.attributes['shard_id'] = self._shard_id >> >>> > result = self._connection_from_session( >> >>> > mapper=self._mapper_zero(), >> >>> > shard_id=self._shard_id).execute( >> >>> > querycontext.statement, >> >>> > self._params >> >>> > ) >> >>> > return self.instances(result, querycontext) >> >>> > >> >>> > >> >>> > >> >>> > >> >>> > >> >>> > >> >>> > Sometimes I got this error: >> >>> > >> >>> > File "/home/anton/Projects/proj/admin/proj/admin/views/stats.py", >> line >> >>> > 898, in _get_filters_from_request >> >>> > control_groups = [g.id for g in >> >>> > User.get_own_groups_query(current_user.id)] >> >>> > File >> >>> > >> >>> > >> "/home/anton/Projects/proj/.venv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", >> >> >>> > line 2802, in __iter__ >> >>> > return self._execute_and_instances(context) >> >>> > File >> >>> > >> >>> > >> "/home/anton/Projects/proj/core/proj/core/orm_extensions/rouing_session.py", >> >> >>> > line 105, in _execute_and_instances >> >>> > shard_id=self._shard_id).execute( >> >>> > File >> >>> > >> >>> > >> "/home/anton/Projects/proj/.venv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", >> >> >>> > line 2806, in _connection_from_session >> >>> > **kw) >> >>> > File >> >>> > >> >>> > >> "/home/anton/Projects/proj/.venv/lib/python2.7/site-packages/sqlalchemy/orm/session.py", >> >> >>> > line 984, in connection >> >>> > bind = self.get_bind(mapper, clause=clause, **kw) >> >>> > File >> >>> > >> >>> > >> "/home/anton/Projects/proj/core/proj/core/orm_extensions/cachingquery.py", >> >>> > line 279, in get_bind >> >>> > original_bind = super(RoutingSession, self).get_bind(mapper, >> clause) >> >>> > File >> >>> > >> >>> > >> "/home/anton/Projects/proj/.venv/lib/python2.7/site-packages/sqlalchemy/orm/session.py", >> >> >>> > line 1336, in get_bind >> >>> > if mapper and mapper.mapped_table.bind: >> >>> > File >> >>> > >> >>> > >> "/home/anton/Projects/proj/.venv/lib/python2.7/site-packages/sqlalchemy/sql/elements.py", >> >> >>> > line 539, in __bool__ >> >>> > raise TypeError("Boolean value of this clause is not defined") >> >>> > TypeError: Boolean value of this clause is not defined >> >>> > >> >>> > >> >>> > >> >>> > >> >>> > I found that `mapper` in original `get_bind` always checks with `is >> not >> >>> > None` condition. There is only one place where condition omitted: >> `if >> >>> > mapper >> >>> > and mapper.mapped_table.bind...`. >> >>> > Possibly it is not correct? Or my code does not do something >> important? >> >>> >> >>> Are you able to catch this error in a debugger? >> >>> >> >>> I'm going to make a wild guess that "mapper" at this point is some >> >>> sort of SQL construct (such as a column object or mapped property), >> >>> rather than an actual mapper. >> >>> >> >>> You don't say which version of SQLAlchemy you are using, but since >> >>> you've overridden _execute_and_instances, I wonder if you need to use >> >>> something like query._bind_mapper() as used by _get_bind_args: >> >>> >> >>> >> >>> < >> https://bitbucket.org/zzzeek/sqlalchemy/src/4b22b01ade6f94cc4db2f2040c802067a25d29a4/lib/sqlalchemy/orm/query.py?at=rel_1_1_14&fileviewer=file-view-default#query.py-2872> >> >> >>> >> >>> Hope that helps, >> >>> >> >>> Simon >> >> >> >> -- >> >> SQLAlchemy - >> >> The Python SQL Toolkit and Object Relational Mapper >> >> >> >> http://www.sqlalchemy.org/ >> >> >> >> To post example code, please provide an MCVE: Minimal, Complete, and >> >> Verifiable Example. See http://stackoverflow.com/help/mcve for a full >> >> description. >> >> --- >> >> You received this message because you are subscribed to the Google >> Groups >> >> "sqlalchemy" group. >> >> To unsubscribe from this group and stop receiving emails from it, send >> an >> > >> email to sqlalchemy+...@googlegroups.com. >> >> To post to this group, send email to sqlal...@googlegroups.com. >> > >> Visit this group at https://groups.google.com/group/sqlalchemy. >> >> For more options, visit https://groups.google.com/d/optout. >> > >> > -- >> > SQLAlchemy - >> > The Python SQL Toolkit and Object Relational Mapper >> > >> > http://www.sqlalchemy.org/ >> > >> > To post example code, please provide an MCVE: Minimal, Complete, and >> Verifiable Example. See http://stackoverflow.com/help/mcve for a full >> description. >> > --- >> > You received this message because you are subscribed to the Google >> Groups "sqlalchemy" group. >> > > To unsubscribe from this group and stop receiving emails from it, send >> an email to sqlalchemy+...@googlegroups.com. >> > To post to this group, send email to sqlal...@googlegroups.com. >> > > Visit this group at https://groups.google.com/group/sqlalchemy. >> > For more options, visit https://groups.google.com/d/optout. >> > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at https://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. > -- Антон -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
