Break scalars() and mappings() into separate objects

The issue of Result.fetchXXX()  methods returning Row
objects unless filtering is applied will not provide a
clear enough API story when type annotations are applied,
so break out scalars/mappings into separate wrapper objects.
this makes some things more intuitive and other things a little
more bumpy.   however the return type story is now clearer.

Fixes: #5503
Change-Id: I629a061823179680dc0723559183859a67ea4db1

1 files changed, 18 insertions, 0 deletions

diff --git a/test/sql/test_resultset.py b/test/sql/test_resultset.py
index 5642797e7..428f71999 100644
--- a/test/sql/test_resultset.py
+++ b/test/sql/test_resultset.py
@@ -316,6 +316,24 @@ class CursorResultTest(fixtures.TablesTest):
         eq_(r[1:], (2, "foo@bar.com"))
         eq_(r[:-1], (1, 2))
 
+    def test_mappings(self, connection):
+        users = self.tables.users
+        addresses = self.tables.addresses
+
+        connection.execute(users.insert(), user_id=1, user_name="john")
+        connection.execute(users.insert(), user_id=2, user_name="jack")
+        connection.execute(
+            addresses.insert(), address_id=1, user_id=2, address="foo@bar.com"
+        )
+
+        r = connection.execute(
+            text("select * from addresses", bind=testing.db)
+        )
+        eq_(
+            r.mappings().all(),
+            [{"address_id": 1, "user_id": 2, "address": "foo@bar.com"}],
+        )
+
     def test_column_accessor_basic_compiled_mapping(self, connection):
         users = self.tables.users