Merge "db: Resolve additional SAWarning warnings" into stable/xena

Author: Zuul

nova/db/main/api.py

@@ -4332,6 +4332,12 @@ def _get_fk_stmts(metadata, conn, table, column, records):
             fk_column = fk_table.c.id
 
         for fk in fk_table.foreign_keys:
+            if table != fk.column.table:
+                # if the foreign key doesn't actually point to the table we're
+                # archiving entries from then it's not relevant; trying to
+                # resolve this would result in a cartesian product
+                continue
+
             # We need to find the records in the referring (child) table that
             # correspond to the records in our (parent) table so we can archive
             # them.
@@ -4378,6 +4384,7 @@ def _get_fk_stmts(metadata, conn, table, column, records):
                 # deque.
                 fk_delete = fk_table.delete().where(fk_column.in_(fk_records))
                 deletes.appendleft(fk_delete)
+
         # Repeat for any possible nested child tables.
         i, d = _get_fk_stmts(metadata, conn, fk_table, fk_column, fk_records)
         inserts.extendleft(i)

nova/objects/cell_mapping.py

@@ -279,11 +279,15 @@ def _get_by_project_id_from_db(context, project_id):
         # SELECT DISTINCT cell_id FROM instance_mappings \
         #   WHERE project_id = $project_id;
         cell_ids = context.session.query(
-            api_db_models.InstanceMapping.cell_id).filter_by(
-            project_id=project_id).distinct().subquery()
+            api_db_models.InstanceMapping.cell_id
+        ).filter_by(
+            project_id=project_id
+        ).distinct()
         # SELECT cell_mappings WHERE cell_id IN ($cell_ids);
-        return context.session.query(api_db_models.CellMapping).filter(
-            api_db_models.CellMapping.id.in_(cell_ids)).all()
+        return context.session.query(
+            api_db_models.CellMapping).filter(
+            api_db_models.CellMapping.id.in_(cell_ids)
+        ).all()
 
     @classmethod
     def get_by_project_id(cls, context, project_id):

nova/tests/fixtures/nova.py

@@ -833,6 +833,16 @@ def setUp(self):
 
         self.addCleanup(warnings.resetwarnings)
 
+        # Enable general SQLAlchemy warnings also to ensure we're not doing
+        # silly stuff. It's possible that we'll need to filter things out here
+        # with future SQLAlchemy versions, but that's a good thing
+
+        warnings.filterwarnings(
+            'error',
+            module='nova',
+            category=sqla_exc.SAWarning,
+        )
+
 
 class ConfPatcher(fixtures.Fixture):
     """Fixture to patch and restore global CONF.