Add prop.secondary to FROM for dynamic loader

Fixed bug where "dynamic" loader needs to explicitly set the "secondary"
table in the FROM clause of the query, to suit the case where the secondary
is a join object that is otherwise not pulled into the query from its
columns alone.

Fixes: #4349
Change-Id: I397f62abd5603efa4fb273586d0f772bf8c8fbbf

diff --git a/doc/build/changelog/unreleased_12/4349.rst b/doc/build/changelog/unreleased_12/4349.rst
new file mode 100644 (file)
index 0000000..a2ce828
--- /dev/null
+++ b/doc/build/changelog/unreleased_12/4349.rst
@@ -0,0 +1,9 @@
+.. change::
+   :tags: bug, orm
+   :tickets: 4349
+
+   Fixed bug where "dynamic" loader needs to explicitly set the "secondary"
+   table in the FROM clause of the query, to suit the case where the secondary
+   is a join object that is otherwise not pulled into the query from its
+   columns alone.
+

diff --git a/lib/sqlalchemy/orm/dynamic.py b/lib/sqlalchemy/orm/dynamic.py
index 73d9ef3bb7fd5eec288a2e5e8011365fe061c2d2..3c59f61d70c3fc58e199ff597823f65a14ef3519 100644 (file)
--- a/lib/sqlalchemy/orm/dynamic.py
+++ b/lib/sqlalchemy/orm/dynamic.py
@@ -219,6 +219,10 @@ class AppenderMixin(object):
 
         mapper = object_mapper(instance)
         prop = mapper._props[self.attr.key]
+
+        if prop.secondary is not None:
+            self._set_select_from([prop.secondary], False)
+
         self._criterion = prop._with_parent(
             instance,
             alias_secondary=False)
@@ -284,6 +288,7 @@ class AppenderMixin(object):
             query = sess.query(self.attr.target_mapper)
 
         query._criterion = self._criterion
+        query._from_obj = self._from_obj
         query._order_by = self._order_by
 
         return query

diff --git a/test/orm/test_dynamic.py b/test/orm/test_dynamic.py
index 8dd805f52963b403a1c0efe2b624d281b8d73b89..5c514ff1a532eac5ec4d9bdb43a5c2b117cbff3b 100644 (file)
--- a/test/orm/test_dynamic.py
+++ b/test/orm/test_dynamic.py
@@ -262,6 +262,36 @@ class DynamicTest(_DynamicFixture, _fixtures.FixtureTest, AssertsCompiledSQL):
             [Item(id=2)]
         )
 
+    def test_secondary_as_join(self):
+        User, users = self.classes.User, self.tables.users
+        items, orders, order_items, Item = (self.tables.items,
+                                            self.tables.orders,
+                                            self.tables.order_items,
+                                            self.classes.Item)
+
+        mapper(User, users, properties={
+            'items': relationship(
+                Item,
+                secondary=order_items.join(orders),
+                lazy="dynamic"
+            )
+        })
+        mapper(Item, items)
+
+        sess = create_session()
+        u1 = sess.query(User).first()
+
+        self.assert_compile(
+            u1.items,
+            "SELECT items.id AS items_id, "
+            "items.description AS items_description "
+            "FROM items, order_items JOIN orders "
+            "ON orders.id = order_items.order_id "
+            "WHERE :param_1 = orders.user_id "
+            "AND items.id = order_items.item_id",
+            use_default_dialect=True
+        )
+
     def test_transient_count(self):
         User, Address = self._user_address_fixture()
         u1 = User()