Keep SQLAlchemy and Django tests in separate DBs

This is because Django's TransactionTest do a TRUNCATE flush at the end to clean up
the database. However, this fails due to SQLAlchemy's ongoing transactions in the DB.
So, it's probably best to keep the 2 types of tests separate for now.

conftest.py

@@ -75,8 +75,30 @@ def fin():
 
 
 @pytest.fixture(scope="session")
-def db(engine, sqlalchemy_connect_url, django_db_setup):
+@pytest.mark.django_db
+def db(
+    request: pytest.FixtureRequest,
+    engine,
+    sqlalchemy_connect_url,
+    django_db_blocker,
+):
     # Bootstrap the DB by running the Django bootstrap version.
+    from django.conf import settings
+    from django.test.utils import setup_databases, teardown_databases
+
+    with django_db_blocker.unblock():
+        # Temporarily reset the database to the SQLAlchemy DBs
+        original_name = settings.DATABASES["default"]["NAME"]
+        original_test_name = settings.DATABASES["default"]["TEST"]["NAME"]
+        settings.DATABASES["default"]["NAME"] = "test_postgres_sqlalchemy"
+        settings.DATABASES["default"]["TEST"]["NAME"] = "test_postgres_sqlalchemy"
+        db_cfg = setup_databases(
+            verbosity=request.config.option.verbose,
+            interactive=False,
+        )
+        settings.DATABASES["default"]["NAME"] = original_name
+        settings.DATABASES["default"]["TEST"]["NAME"] = original_test_name
+
     database_url = sqlalchemy_connect_url
     if not database_exists(database_url):
         raise RuntimeError(f"SQLAlchemy cannot connect to DB at {database_url}")
@@ -104,6 +126,17 @@ def db(engine, sqlalchemy_connect_url, django_db_setup):
         bind=engine
     )
 
+    yield
+
+    try:
+        teardown_databases(db_cfg, verbosity=request.config.option.verbose)
+    except Exception as exc:  # noqa: BLE001
+        request.node.warn(
+            pytest.PytestWarning(
+                f"Error when trying to teardown test databases: {exc!r}"
+            )
+        )
+
 
 @pytest.fixture
 def dbsession(db, engine):

pytest.ini

@@ -1,6 +1,6 @@
 [pytest]
 DJANGO_SETTINGS_MODULE = django_scaffold.tests_settings
-addopts = --sqlalchemy-connect-url="postgresql://postgres@postgres:5432/test_postgres" --ignore-glob=**/test_results*
+addopts = --sqlalchemy-connect-url="postgresql://postgres@postgres:5432/test_postgres_sqlalchemy" --ignore-glob=**/test_results*
 markers=
     integration: integration tests (includes tests with vcrs)
     real_checkpoint_logger: prevents use of stubbed CheckpointLogger