- remove .columns method on UpdateBase since a returning()

construct isn't intended to be used in SELECT queries directly
- implement a direct system within CTE to detect UpdateBase and
extract columns from returning directly

3 files changed, 10 insertions, 11 deletions

diff --git a/lib/sqlalchemy/sql/dml.py b/lib/sqlalchemy/sql/dml.py
index a4a362c22..8f368dcdb 100644
--- a/lib/sqlalchemy/sql/dml.py
+++ b/lib/sqlalchemy/sql/dml.py
@@ -144,16 +144,6 @@ class UpdateBase(
         """
         self._returning = cols
 
-    @util.memoized_property
-    def columns(self):
-        """A select-style column collection from the RETURNING
-        expression of this clause."""
-
-        self._columns = ColumnCollection()
-        for col in self._returning:
-            col._make_proxy(self)
-        return self._columns.as_immutable()
-
     @_generative
     def with_hint(self, text, selectable=None, dialect_name="*"):
         """Add a table hint for a single table to this
diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py
index f3ef16974..5e709b1e3 100644
--- a/lib/sqlalchemy/sql/schema.py
+++ b/lib/sqlalchemy/sql/schema.py
@@ -1396,7 +1396,7 @@ class Column(SchemaItem, ColumnClause):
         selectable._columns.add(c)
         if selectable._is_clone_of is not None:
             c._is_clone_of = selectable._is_clone_of.columns[c.key]
-        if self.primary_key and hasattr(selectable, 'primary_key'):
+        if self.primary_key:
             selectable.primary_key.add(c)
         c.dispatch.after_parent_attach(c, selectable)
         return c
diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index 95ed10524..4315abc47 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -1195,6 +1195,15 @@ class CTE(Generative, HasSuffixes, Alias):
             self._suffixes = _suffixes
         super(CTE, self).__init__(selectable, name=name)
 
+    @util.dependencies("sqlalchemy.sql.dml")
+    def _populate_column_collection(self, dml):
+        if isinstance(self.element, dml.UpdateBase):
+            for col in self.element._returning:
+                col._make_proxy(self)
+        else:
+            for col in self.element.columns._all_columns:
+                col._make_proxy(self)
+
     def alias(self, name=None, flat=False):
         return CTE(
             self.original,