Re: [Sqlalchemy-tickets] [sqlalchemy] #2887: subqueryload query invokes ahead of parent loader init, can cause conflicts

[sqlalchemy <mi...@zz...>]

#2887: subqueryload query invokes ahead of parent loader init, can cause conflicts
------------------------------+-------------------------------
      Reporter:  zzzeek       |      Owner:  zzzeek
          Type:  defect       |     Status:  new
      Priority:  high         |  Milestone:  0.8.xx
     Component:  orm          |   Severity:  major - 1-3 hours
    Resolution:               |   Keywords:
Progress State:  in progress  |
------------------------------+-------------------------------

Comment (by zzzeek):

 we can address that issue by adding a "make sure we run the subq loader"
 function like this:

 {{{
 #!diff
 @@ -962,7 +969,13 @@ class SubqueryLoader(AbstractRelationshipLoader):
              state.get_impl(self.key).\
                      set_committed_value(state, dict_, collection)

 -        return load_collection_from_subq, None, None
 +        def _make_sure_its_loaded(state, dict_, row):
 +                collections.get(
 +                tuple([row[col] for col in local_cols]),
 +                ()
 +            )
 +
 +        return load_collection_from_subq, None, None,
 _make_sure_its_loaded

      def _create_scalar_loader(self, collections, local_cols):
          def load_scalar_from_subq(state, dict_, row):
 @@ -980,7 +993,13 @@ class SubqueryLoader(AbstractRelationshipLoader):
              state.get_impl(self.key).\
                      set_committed_value(state, dict_, scalar)

 -        return load_scalar_from_subq, None, None
 +        def _make_sure_its_loaded(state, dict_, row):
 +            collections.get(
 +                tuple([row[col] for col in local_cols]),
 +                ()
 +            )
 +
 +        return load_scalar_from_subq, None, None, _make_sure_its_loaded


 }}}

 additional issues remain with some self-referential loading

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2887#comment:2>
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