I am currently unit testing my code with a mocking library. I am now at the point where I want to test that everything plays nicely with the database and works as expected.
Does it make sense to copy a lot of my unit tests and adjust them to use a test database?
Depends on the tests, we’d need more detail about what they’re doing.
However, if you just copy the tests you now have to maintain both copies. Perhaps you can have the same tests run in two modes. One mode uses a mocked infrastructure, the other using real (test) infrastructure. How you accomplish this depends on how you’ve done the mocking and how your configuration system works.