- Adjusted the logic which applies names to the .c collection when

a no-name :class:`.BindParameter` is received, e.g. via :func:`.sql.literal`
or similar; the "key" of the bind param is used as the key within
.c. rather than the rendered name.  Since these binds have "anonymous"
names in any case, this allows individual bound parameters to
have their own name within a selectable if they are otherwise unlabeled.
fixes #2974

4 files changed, 29 insertions, 9 deletions

diff --git a/doc/build/changelog/changelog_09.rst b/doc/build/changelog/changelog_09.rst
index 9a1ff9f27..a5c22aefc 100644
--- a/doc/build/changelog/changelog_09.rst
+++ b/doc/build/changelog/changelog_09.rst
@@ -18,6 +18,17 @@
         :tags: bug, sql
         :tickets: 2974
 
+        Adjusted the logic which applies names to the .c collection when
+        a no-name :class:`.BindParameter` is received, e.g. via :func:`.sql.literal`
+        or similar; the "key" of the bind param is used as the key within
+        .c. rather than the rendered name.  Since these binds have "anonymous"
+        names in any case, this allows individual bound parameters to
+        have their own name within a selectable if they are otherwise unlabeled.
+
+    .. change::
+        :tags: bug, sql
+        :tickets: 2974
+
         Some changes to how the :attr:`.FromClause.c` collection behaves
         when presented with duplicate columns.  The behavior of emitting a
         warning and replacing the old column with the same name still
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py
index 1b49a7cd1..f2ce0619c 100644
--- a/lib/sqlalchemy/sql/elements.py
+++ b/lib/sqlalchemy/sql/elements.py
@@ -588,7 +588,7 @@ class ColumnElement(ClauseElement, operators.ColumnOperators):
     primary_key = False
     foreign_keys = []
     _label = None
-    _key_label = None
+    _key_label = key = None
     _alt_names = ()
 
     def self_group(self, against=None):
@@ -681,10 +681,14 @@ class ColumnElement(ClauseElement, operators.ColumnOperators):
         """
         if name is None:
             name = self.anon_label
-            try:
-                key = str(self)
-            except exc.UnsupportedCompilationError:
-                key = self.anon_label
+            if self.key:
+                key = self.key
+            else:
+                try:
+                    key = str(self)
+                except exc.UnsupportedCompilationError:
+                    key = self.anon_label
+
         else:
             key = name
         co = ColumnClause(
@@ -755,7 +759,6 @@ class ColumnElement(ClauseElement, operators.ColumnOperators):
                                 'name', 'anon')))
 
 
-
 class BindParameter(ColumnElement):
     """Represent a "bound expression".
 
diff --git a/test/sql/test_compiler.py b/test/sql/test_compiler.py
index 25aa78b03..b1c807df6 100644
--- a/test/sql/test_compiler.py
+++ b/test/sql/test_compiler.py
@@ -2082,6 +2082,10 @@ class SelectTest(fixtures.TestBase, AssertsCompiledSQL):
         )
 
     def test_naming(self):
+        # TODO: the part where we check c.keys() are  not "compile" tests, they
+        # belong probably in test_selectable, or some broken up
+        # version of that suite
+
         f1 = func.hoho(table1.c.name)
         s1 = select([table1.c.myid, table1.c.myid.label('foobar'),
                     f1,
@@ -2098,7 +2102,8 @@ class SelectTest(fixtures.TestBase, AssertsCompiledSQL):
         exprs = (
             table1.c.myid == 12,
             func.hoho(table1.c.myid),
-            cast(table1.c.name, Numeric)
+            cast(table1.c.name, Numeric),
+            literal('x'),
         )
         for col, key, expr, label in (
             (table1.c.name, 'name', 'mytable.name', None),
@@ -2108,7 +2113,8 @@ class SelectTest(fixtures.TestBase, AssertsCompiledSQL):
                         'CAST(mytable.name AS NUMERIC)', 'anon_1'),
             (t1.c.col1, 'col1', 'mytable.col1', None),
             (column('some wacky thing'), 'some wacky thing',
-                '"some wacky thing"', '')
+                '"some wacky thing"', ''),
+            (exprs[3], exprs[3].key, ":param_1", "anon_1")
         ):
             if getattr(col, 'table', None) is not None:
                 t = col.table
diff --git a/test/sql/test_update.py b/test/sql/test_update.py
index 10306372b..a1b64d862 100644
--- a/test/sql/test_update.py
+++ b/test/sql/test_update.py
@@ -203,7 +203,7 @@ class UpdateTest(_UpdateFromTestBase, fixtures.TablesTest, AssertsCompiledSQL):
         """
         table1 = self.tables.mytable
         expr = func.foo(table1.c.myid)
-        assert not hasattr(expr, 'key')
+        eq_(expr.key, None)
         self.assert_compile(table1.update().values({expr: 'bar'}),
             'UPDATE mytable SET foo(myid)=:param_1')