unit tests, yeah, but if you try to get "the most bang for the buck" in like "test a lot with zero/little effort" you'll end up with a layer of "integration tests": that (1) set stuff in db, (2) do stuff, (3) read stuff from db and assert its correctness... A sane ORM would not actively hinder this scenario even cross-dbs or with memory-mocked-dbs, but Django's does!