1 files changed, 6 insertions, 0 deletions
diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index 01d617259..bda3d655e 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -137,6 +137,10 @@ class FromClause(Selectable):
     named_with_column = False
     _hide_froms = []
 
+    _textual = False
+    """a marker that allows us to easily distinguish a :class:`.TextAsFrom`
+    or similar object from other kinds of :class:`.FromClause` objects."""
+
     schema = None
     """Define the 'schema' attribute for this :class:`.FromClause`.
 
@@ -3046,6 +3050,8 @@ class TextAsFrom(SelectBase):
     """
     __visit_name__ = "text_as_from"
 
+    _textual = True
+
     def __init__(self, text, columns):
         self.element = text
         self.column_args = columns