TDD Database migration code

My google searches are giving me bad results... :(

Does anyone know of any good articles, or have any good hints, on how to do TDD for writing PostgresSQL, or database code?

I need to write a custom system which allows us to do DB migrations and updates etc, a bit similar to what Ruby on Rails with has their DB rake:migration command.*

Google is mostly giving me information on how to abstract out DB objects, but I need to verify that my new custom migration system is actually working.

The tests I would want to write are simples
   1. Confirm that a migration file worked (say by adding a column)
   2. Confirm that only the latest migration was run, and not a previous one (say by checking a value in the table wasn't changed)

I appreciate the help you can provide.

*The short version is:
 1. A command which generates a .sql file with a timestamp in the file name.
  2. A command which checks all the files in a folder, and then does some comparisons to another db, and picks one or more .sql files to run on the db in question.