db: Don't pass strings to Connection.execute()

Resolve the following RemovedIn20Warning warning:

  Passing a string to Connection.execute() is deprecated and will be
  removed in version 2.0.  Use the text() construct, or the
  Connection.exec_driver_sql() method to invoke a driver-level SQL
  string.

We do the latter.

Change-Id: I0ee518022772beeb0298e12b5b36279fd384fb4a
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

masakari/db/sqlalchemy/api.py

@@ -23,8 +23,8 @@ from oslo_db.sqlalchemy import enginefacade
 from oslo_db.sqlalchemy import utils as sqlalchemyutils
 from oslo_log import log as logging
 from oslo_utils import timeutils
-from sqlalchemy import or_, and_
-from sqlalchemy.ext.compiler import compiles
+import sqlalchemy as sa
+from sqlalchemy.ext import compiler
 from sqlalchemy import MetaData
 from sqlalchemy.orm import joinedload
 from sqlalchemy import sql
@@ -736,7 +736,7 @@ class DeleteFromSelect(sa_sql.expression.UpdateBase):
 
 # NOTE(pooja_jadhav): MySQL doesn't yet support subquery with
 # 'LIMIT & IN/ALL/ANY/SOME' We need work around this with nesting select.
-@compiles(DeleteFromSelect)
+@compiler.compiles(DeleteFromSelect)
 def visit_delete_from_select(element, compiler, **kw):
     return "DELETE FROM %s WHERE %s in (SELECT T1.%s FROM (%s) as T1)" % (
         compiler.process(element.table, asfrom=True),
@@ -774,7 +774,7 @@ def purge_deleted_rows(context, age_in_days, max_rows):
         if table.name == 'notifications':
             status_column = table.c.status
             query_delete = sql.select([column]).where(
-                and_(updated_at_column < deleted_age, or_(
+                sa.and_(updated_at_column < deleted_age, sa.or_(
                     status_column == 'finished', status_column == 'failed',
                     status_column == 'ignored'))).order_by(status_column)
         else:

masakari/tests/fixtures.py

@@ -188,13 +188,6 @@ class WarningsFixture(fixtures.Fixture):
             category=sqla_exc.SADeprecationWarning,
         )
 
-        warnings.filterwarnings(
-            'ignore',
-            message=r'Passing a string to Connection.execute\(\)',
-            module='masakari',
-            category=sqla_exc.SADeprecationWarning,
-        )
-
         warnings.filterwarnings(
             'ignore',
             message=r'The legacy calling style of select\(\)',

masakari/tests/unit/db/test_purge.py

@@ -111,7 +111,7 @@ class PurgeDeletedTest(test.TestCase):
 
         dialect = self.engine.url.get_dialect()
         if dialect == sqlite.dialect:
-            self.conn.execute("PRAGMA foreign_keys = ON")
+            self.conn.exec_driver_sql("PRAGMA foreign_keys = ON")
 
     def _count(self, table):
         return self.conn.execute(