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-rw-r--r--lib/sqlalchemy/sql/annotation.py17
-rw-r--r--lib/sqlalchemy/sql/selectable.py30
-rw-r--r--lib/sqlalchemy/sql/util.py4
3 files changed, 44 insertions, 7 deletions
diff --git a/lib/sqlalchemy/sql/annotation.py b/lib/sqlalchemy/sql/annotation.py
index 43ca84abb..3ce524447 100644
--- a/lib/sqlalchemy/sql/annotation.py
+++ b/lib/sqlalchemy/sql/annotation.py
@@ -421,6 +421,7 @@ def _deep_annotate(
annotations: _AnnotationDict,
exclude: Optional[Sequence[SupportsAnnotations]] = None,
detect_subquery_cols: bool = False,
+ ind_cols_on_fromclause: bool = False,
) -> _SA:
"""Deep copy the given ClauseElement, annotating each element
with the given annotations dictionary.
@@ -435,6 +436,16 @@ def _deep_annotate(
cloned_ids: Dict[int, SupportsAnnotations] = {}
def clone(elem: SupportsAnnotations, **kw: Any) -> SupportsAnnotations:
+
+ # ind_cols_on_fromclause means make sure an AnnotatedFromClause
+ # has its own .c collection independent of that which its proxying.
+ # this is used specifically by orm.LoaderCriteriaOption to break
+ # a reference cycle that it's otherwise prone to building,
+ # see test_relationship_criteria->
+ # test_loader_criteria_subquery_w_same_entity. logic here was
+ # changed for #8796 and made explicit; previously it occurred
+ # by accident
+
kw["detect_subquery_cols"] = detect_subquery_cols
id_ = id(elem)
@@ -454,7 +465,11 @@ def _deep_annotate(
newelem = elem._annotate(annotations)
else:
newelem = elem
- newelem._copy_internals(clone=clone)
+
+ newelem._copy_internals(
+ clone=clone, ind_cols_on_fromclause=ind_cols_on_fromclause
+ )
+
cloned_ids[id_] = newelem
return newelem
diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index 488dfe721..3d3aea3f2 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -6752,8 +6752,28 @@ TextAsFrom = TextualSelect
class AnnotatedFromClause(Annotated):
- def __init__(self, element, values):
- # force FromClause to generate their internal
- # collections into __dict__
- element.c
- Annotated.__init__(self, element, values)
+ def _copy_internals(self, **kw):
+ super()._copy_internals(**kw)
+ if kw.get("ind_cols_on_fromclause", False):
+ ee = self._Annotated__element # type: ignore
+
+ self.c = ee.__class__.c.fget(self) # type: ignore
+
+ @util.ro_memoized_property
+ def c(self) -> ReadOnlyColumnCollection[str, KeyedColumnElement[Any]]:
+ """proxy the .c collection of the underlying FromClause.
+
+ Originally implemented in 2008 as a simple load of the .c collection
+ when the annotated construct was created (see d3621ae961a), in modern
+ SQLAlchemy versions this can be expensive for statements constructed
+ with ORM aliases. So for #8796 SQLAlchemy 2.0 we instead proxy
+ it, which works just as well.
+
+ Two different use cases seem to require the collection either copied
+ from the underlying one, or unique to this AnnotatedFromClause.
+
+ See test_selectable->test_annotated_corresponding_column
+
+ """
+ ee = self._Annotated__element # type: ignore
+ return ee.c # type: ignore
diff --git a/lib/sqlalchemy/sql/util.py b/lib/sqlalchemy/sql/util.py
index 55c6a35f8..623a3f896 100644
--- a/lib/sqlalchemy/sql/util.py
+++ b/lib/sqlalchemy/sql/util.py
@@ -1197,7 +1197,9 @@ class ClauseAdapter(visitors.ReplacingExternalTraversal):
elif self.exclude_fn and self.exclude_fn(col):
return None
else:
- return self._corresponding_column(col, True) # type: ignore
+ return self._corresponding_column( # type: ignore
+ col, require_embedded=True
+ )
class _ColumnLookup(Protocol):