diff --git a/swh/storage/tests/test_api_client.py b/swh/storage/tests/test_api_client.py
--- a/swh/storage/tests/test_api_client.py
+++ b/swh/storage/tests/test_api_client.py
@@ -3,6 +3,7 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+from contextlib import contextmanager
 import shutil
 import tempfile
 import unittest
@@ -16,6 +17,7 @@
 from swh.storage.api.server import app
 from swh.storage.in_memory import Storage as InMemoryStorage
 import swh.storage.storage
+from swh.storage.db import Db
 from swh.storage.tests.test_storage import \
     CommonTestStorage, CommonPropTestStorage, StorageTestDbFixture
 
@@ -73,6 +75,10 @@
         self.reset_db_tables(self.TEST_DB_NAME, excluded=excluded)
         self.journal_writer.objects[:] = []
 
+    @contextmanager
+    def get_db(self):
+        yield Db(self.conn)
+
 
 class RemoteMemStorageFixture(ServerTestFixture, unittest.TestCase):
     def setUp(self):
diff --git a/swh/storage/tests/test_storage.py b/swh/storage/tests/test_storage.py
--- a/swh/storage/tests/test_storage.py
+++ b/swh/storage/tests/test_storage.py
@@ -4,6 +4,7 @@
 # See top-level LICENSE file for more information
 
 import copy
+from contextlib import contextmanager
 import datetime
 import itertools
 import queue
@@ -46,6 +47,15 @@
             self.storage._pool.closeall()
         super().tearDown()
 
+    def get_db(self):
+        return self.storage.db()
+
+    @contextmanager
+    def db_transaction(self):
+        with self.get_db() as db:
+            with db.transaction() as cur:
+                yield db, cur
+
 
 class TestStorageData:
     def setUp(self, *args, **kwargs):