title: Rails test data, in the database
body: <p>This might be a basic misunderstanding on my part. I have a bunch of logic in my app which collects sets of data from several tables and combines them into memory structures. I want to write tests for that logic.</p>
  <p>It seems to me that fixtures, factory girl and similar tools build in-memory model instances. If I do activerecord calls, like <code>Model.find(foo: 12)</code> won't those apply only against records that were saved?</p>