Updates for MariaDB sequences

MariaDB should not run a Sequence if it has optional=True.
Additionally, rework the rules in crud.py to accommodate the
new combination MariaDB brings us, which is a dialect
that supports both cursor.lastrowid, explicit sequences,
*and* no support for returning.

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #5528
Change-Id: I9a8ea69a34983affa95dfd22186e2908fdf0d58c

1 files changed, 24 insertions, 0 deletions

diff --git a/test/sql/test_returning.py b/test/sql/test_returning.py
index 7d60dd475..20aa1fb3a 100644
--- a/test/sql/test_returning.py
+++ b/test/sql/test_returning.py
@@ -430,6 +430,30 @@ class ReturnDefaultsTest(fixtures.TablesTest):
             [None],
         )
 
+    def test_insert_sql_expr(self, connection):
+        from sqlalchemy import literal
+
+        t1 = self.tables.t1
+        result = connection.execute(
+            t1.insert().return_defaults().values(insdef=literal(10) + 5)
+        )
+
+        eq_(
+            result.returned_defaults._mapping,
+            {"id": 1, "data": None, "insdef": 15, "upddef": None},
+        )
+
+    def test_update_sql_expr(self, connection):
+        from sqlalchemy import literal
+
+        t1 = self.tables.t1
+        connection.execute(t1.insert().values(upddef=1))
+        result = connection.execute(
+            t1.update().values(upddef=literal(10) + 5).return_defaults()
+        )
+
+        eq_(result.returned_defaults._mapping, {"upddef": 15})
+
     def test_insert_non_default_plus_default(self, connection):
         t1 = self.tables.t1
         result = connection.execute(