- Fixed bug in new :class:`.TextAsFrom` construct where :class:`.Column`-

oriented row lookups were not matching up to the ad-hoc :class:`.ColumnClause`
objects that :class:`.TextAsFrom` generates, thereby making it not
usable as a target in :meth:`.Query.from_statement`.  Also fixed
:meth:`.Query.from_statement` mechanics to not mistake a :class:`.TextAsFrom`
for a :class:`.Select` construct.  This bug is also an 0.9 regression
as the :meth:`.Text.columns` method is called to accommodate the
:paramref:`.text.typemap` argument. [ticket:2932]

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