Add result map targeting for custom compiled, text objects

In order for text(), custom compiled objects, etc. to be usable
by Query(), they are all targeted by object key in the result map.
As we no longer want Query to implicitly label these, as well as that
text() has no label feature, support adding entries to the result
map that have no name, key, or type, only the object itself, and
then ensure that the compiler sets up for positional targeting
when this condition is detected.

Allows for more flexible ORM query usage with custom expressions
and text() while having less special logic in query itself.

Fixes: #4887
Change-Id: Ie073da127d292d43cb132a2b31bc90af88bfe2fd

1 files changed, 8 insertions, 4 deletions

diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index ddbcdf91d..6282cf2ee 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -4191,8 +4191,9 @@ class Select(
 
             def name_for_col(c):
                 if c._label is None or not c._render_label_in_columns_clause:
-                    return (None, c)
+                    return (None, c, False)
 
+                repeated = False
                 name = c._label
 
                 if name in names:
@@ -4218,19 +4219,22 @@ class Select(
                             # subsequent occurrences of the column so that the
                             # original stays non-ambiguous
                             name = c._dedupe_label_anon_label
+                            repeated = True
                         else:
                             names[name] = c
                     elif anon_for_dupe_key:
                         # same column under the same name. apply the "dedupe"
                         # label so that the original stays non-ambiguous
                         name = c._dedupe_label_anon_label
+                        repeated = True
                 else:
                     names[name] = c
-                return name, c
+                return name, c, repeated
 
             return [name_for_col(c) for c in cols]
         else:
-            return [(None, c) for c in cols]
+            # repeated name logic only for use labels at the moment
+            return [(None, c, False) for c in cols]
 
     @_memoized_property
     def _columns_plus_names(self):
@@ -4245,7 +4249,7 @@ class Select(
         keys_seen = set()
         prox = []
 
-        for name, c in self._generate_columns_plus_names(False):
+        for name, c, repeated in self._generate_columns_plus_names(False):
             if not hasattr(c, "_make_proxy"):
                 continue
             if name is None: