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| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2019-09-30 21:26:08 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2019-10-01 16:11:34 -0400 |
| commit | 9a2a0f324c13b5a1b334a3982a766cb9f21f428e (patch) | |
| tree | f4548faa2cf60f07d2e13e6eb1b137ff1d3e072d /lib/sqlalchemy/orm/loading.py | |
| parent | a3c964203e61f8deeb559b15a78cc640dee67012 (diff) | |
| download | sqlalchemy-9a2a0f324c13b5a1b334a3982a766cb9f21f428e.tar.gz | |
Cancel polymorphic loading in optimized get
Since optimized_get for inheriting mappers writes a simple
SELECT, we need to cancel out any with_polymorphic selectables
that interfere with simple column lookup. While adaptation is
another option, just removing the with_polymorphic is much
simpler. The issue is not noticeable unless the ResultProxy
is not allowing "key fallback" column lookups, which will
be the case when this behavior is deprecated.
Fixes: #4718
Change-Id: I8fa2f5c0434b6a681813a92ac71fe12712f5d634
Diffstat (limited to 'lib/sqlalchemy/orm/loading.py')
| -rw-r--r-- | lib/sqlalchemy/orm/loading.py | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/lib/sqlalchemy/orm/loading.py b/lib/sqlalchemy/orm/loading.py index 94a9b8d22..886240591 100644 --- a/lib/sqlalchemy/orm/loading.py +++ b/lib/sqlalchemy/orm/loading.py @@ -23,6 +23,7 @@ from . import strategy_options from .base import _DEFER_FOR_STATE from .base import _SET_DEFERRED_EXPIRED from .util import _none_set +from .util import aliased from .util import state_str from .. import exc as sa_exc from .. import util @@ -633,7 +634,6 @@ def _instance_processor( if mapper.polymorphic_map and not _polymorphic_from and not refresh_state: # if we are doing polymorphic, dispatch to a different _instance() # method specific to the subclass mapper - def ensure_no_pk(row): identitykey = ( identity_class, @@ -957,9 +957,10 @@ def load_scalar_attributes(mapper, state, attribute_names): # by default statement = mapper._optimized_get_statement(state, attribute_names) if statement is not None: + wp = aliased(mapper, statement) result = load_on_ident( - session.query(mapper) - .options(strategy_options.Load(mapper).undefer("*")) + session.query(wp) + .options(strategy_options.Load(wp).undefer("*")) .from_statement(statement), None, only_load_props=attribute_names, |