Pickling fixes for ORM / Core

Fixed regression where ORM loaded objects could not be pickled in cases
where loader options making use of ``"*"`` were used in certain
combinations, such as combining the :func:`_orm.joinedload` loader strategy
with ``raiseload('*')`` of sub-elements.

Fixes: #7134

Fixed issue where SQL queries using the
:meth:`_functions.FunctionElement.within_group` construct could not be
pickled, typically when using the ``sqlalchemy.ext.serializer`` extension
but also for general generic pickling.

Fixes: #6520

Change-Id: Ib73fd49c875e6da9898493c190f610e68b88ec72

1 files changed, 25 insertions, 0 deletions

diff --git a/test/sql/test_functions.py b/test/sql/test_functions.py
index 43b505c99..f3fb724c0 100644
--- a/test/sql/test_functions.py
+++ b/test/sql/test_functions.py
@@ -542,6 +542,31 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
             "row_number() OVER ()",
         )
 
+    def test_pickle_within_group(self):
+        """test #6520"""
+
+        # TODO: the test/sql package lacks a comprehensive pickling
+        # test suite even though there are __reduce__ methods in several
+        # places in sql/elements.py.   likely as part of
+        # test/sql/test_compare.py might be a place this can happen but
+        # this still relies upon a strategy for table metadata as we have
+        # in serializer.
+
+        f1 = func.percentile_cont(literal(1)).within_group()
+
+        self.assert_compile(
+            util.pickle.loads(util.pickle.dumps(f1)),
+            "percentile_cont(:param_1) WITHIN GROUP (ORDER BY )",
+        )
+
+        f1 = func.percentile_cont(literal(1)).within_group(
+            column("q"), column("p").desc()
+        )
+        self.assert_compile(
+            util.pickle.loads(util.pickle.dumps(f1)),
+            "percentile_cont(:param_1) WITHIN GROUP (ORDER BY q, p DESC)",
+        )
+
     def test_functions_with_cols(self):
         users = table(
             "users", column("id"), column("name"), column("fullname")