Turn off the is_literal flag when proxying literal_column() to Label

Fixed a series of quoting issues which all stemmed from the concept of the
:func:`.literal_column` construct, which when being "proxied" through a
subquery to be referred towards by a label that matches its text, the label
would not have quoting rules applied to it, even if the string in the
:class:`.Label` were set up as a :class:`.quoted_name` construct.  Not
applying quoting to the text of the :class:`.Label` is a bug because this
text is strictly a SQL identifier name and not a SQL expression, and the
string should not have quotes embedded into it already unlike the
:func:`.literal_column` which it may be applied towards.   The existing
behavior of a non-labeled :func:`.literal_column` being propagated as is on
the outside of a subquery is maintained in order to help with manual
quoting schemes, although it's not clear if valid SQL can be generated for
such a construct in any case.

Fixes: #4730
Change-Id: I300941f27872fc4298c74a1d1ed65aef1a5cdd82

1 files changed, 42 insertions, 2 deletions

diff --git a/test/sql/test_text.py b/test/sql/test_text.py
index afc775598..f6b3b0519 100644
--- a/test/sql/test_text.py
+++ b/test/sql/test_text.py
@@ -19,6 +19,7 @@ from sqlalchemy import text
 from sqlalchemy import union
 from sqlalchemy import util
 from sqlalchemy.sql import column
+from sqlalchemy.sql import quoted_name
 from sqlalchemy.sql import table
 from sqlalchemy.sql import util as sql_util
 from sqlalchemy.testing import assert_raises_message
@@ -27,7 +28,6 @@ from sqlalchemy.testing import eq_
 from sqlalchemy.testing import fixtures
 from sqlalchemy.types import NullType
 
-
 table1 = table(
     "mytable",
     column("myid", Integer),
@@ -136,7 +136,9 @@ class SelectCompositionTest(fixtures.TestBase, AssertsCompiledSQL):
     def test_select_composition_six(self):
         # test that "auto-labeling of subquery columns"
         # doesn't interfere with literal columns,
-        # exported columns don't get quoted
+        # exported columns don't get quoted.
+        # [ticket:4730] refines this but for the moment the behavior with
+        # no columns is being maintained.
         self.assert_compile(
             select(
                 [
@@ -708,6 +710,44 @@ class OrderByLabelResolutionTest(fixtures.TestBase, AssertsCompiledSQL):
             "GROUP BY anon_1.myid",
         )
 
+    def test_order_by_literal_col_quoting_one(self):
+        col = literal_column("SUM(ABC)").label("SUM(ABC)")
+        tbl = table("my_table")
+        query = select([col]).select_from(tbl).order_by(col)
+        self.assert_compile(
+            query,
+            'SELECT SUM(ABC) AS "SUM(ABC)" FROM my_table ORDER BY "SUM(ABC)"',
+        )
+
+    def test_order_by_literal_col_quoting_two(self):
+        col = literal_column("SUM(ABC)").label("SUM(ABC)_")
+        tbl = table("my_table")
+        query = select([col]).select_from(tbl).order_by(col)
+        self.assert_compile(
+            query,
+            'SELECT SUM(ABC) AS "SUM(ABC)_" FROM my_table ORDER BY '
+            '"SUM(ABC)_"',
+        )
+
+    def test_order_by_literal_col_quoting_one_explict_quote(self):
+        col = literal_column("SUM(ABC)").label(quoted_name("SUM(ABC)", True))
+        tbl = table("my_table")
+        query = select([col]).select_from(tbl).order_by(col)
+        self.assert_compile(
+            query,
+            'SELECT SUM(ABC) AS "SUM(ABC)" FROM my_table ORDER BY "SUM(ABC)"',
+        )
+
+    def test_order_by_literal_col_quoting_two_explicit_quote(self):
+        col = literal_column("SUM(ABC)").label(quoted_name("SUM(ABC)_", True))
+        tbl = table("my_table")
+        query = select([col]).select_from(tbl).order_by(col)
+        self.assert_compile(
+            query,
+            'SELECT SUM(ABC) AS "SUM(ABC)_" FROM my_table ORDER BY '
+            '"SUM(ABC)_"',
+        )
+
     def test_order_by_func_label_desc(self):
         stmt = select([func.foo("bar").label("fb"), table1]).order_by(
             desc("fb")