If you are using foreign keys in your Rails application, it’s easy to come across the situation where your application crashes due to an attempt to destroy a resource which id is a foreign key of another one. Trying to handle these situations on a case-by-case basis is quite painful, but with a very simple trick we can rest assured that it won’t happen.

http://waiting-for-dev.github.io/blog/2015/02/03/rails-rescue-from-all-foreign-key-violations-at-once/