The concepts of unit test and integration test are well-defined: the former tests one component, the latter tests more than one component.
I use Effort to test my Entity Framework repositories. Effort is an in-memory database implementation, so we don't hit an actual database but just the memory so it's faster.
I'm testing solely my repositories by creating some fake data and populating an in-memory database with this fake data. I'm not mocking the data context. Should these be considered unit tests or integration tests?
Edit: I'm testing the methods of my repositories - e.g. CustomerRepository.GetAllCustomers. I'm populating this in-memory database with (say) 5 customers, calling the method, and asserting that I get those 5 customers back.