migration_data (rubygems): Sometimes we have to write some Rails code in the migrations and it's hard to                           keep them in working state because models wich are used there changes too often. there                           some techniques which help to avoid these pitfalls. For example, define model                           classes in the migrations or write raw SQL. But they don't help in 100% cases anyway.                           This gem promises to solve the problem in a simple way.
Keywords: data|data-migration|migrations|rails