Support filter_by() from columns, functions, Core SQL

Fixed regression where :meth:`_orm.Query.filter_by` would not work if the
lead entity were a SQL function or other expression derived from the
primary entity in question, rather than a simple entity or column of that
entity. Additionally, improved the behavior of
:meth:`_sql.Select.filter_by` overall to work with column expressions even
in a non-ORM context.

Fixes: #6414
Change-Id: I316b5bf98293bec1ede08787f6181dd14be85419

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/functions.py b/lib/sqlalchemy/sql/functions.py
index 02ed55100..0aa870ce4 100644
--- a/lib/sqlalchemy/sql/functions.py
+++ b/lib/sqlalchemy/sql/functions.py
@@ -15,6 +15,7 @@ from . import roles
 from . import schema
 from . import sqltypes
 from . import util as sqlutil
+from .base import _entity_namespace
 from .base import ColumnCollection
 from .base import Executable
 from .base import Generative
@@ -618,6 +619,16 @@ class FunctionElement(Executable, ColumnElement, FromClause, Generative):
         else:
             return super(FunctionElement, self).self_group(against=against)
 
+    @property
+    def entity_namespace(self):
+        """overrides FromClause.entity_namespace as functions are generally
+        column expressions and not FromClauses.
+
+        """
+        # ideally functions would not be fromclauses but we failed to make
+        # this adjustment in 1.4
+        return _entity_namespace(self.clause_expr)
+
 
 class FunctionAsBinary(BinaryExpression):
     _traverse_internals = [