Blogmark

It's cool to read through the internals of different rake tasks that are available for interacting with a Rails database and database migrations.

For instance, you can see how db:migrate works:

  desc "Migrate the database (options: VERSION=x, VERBOSE=false, SCOPE=blog)."
  task migrate: :load_config do
    ActiveRecord::Tasks::DatabaseTasks.migrate_all
    db_namespace["_dump"].invoke
  end

First, it attempts to run all your migrations. Then it invokes _dump which is an internal task for re-generating your schema.rb (or structure.sql) based on the latest DB schema changes.