Question

How can I write a Rails migration to rename an ActiveRecord subclass when the models are stored in the database using single table inheritance (STI)? The only thing I can think of is to use a raw sql update statement to change the value of type column value from the old subtype name to the new one.

Answer 1

You can use execute to run raw queries in the migrations

class YourMigration < ActiveRecord::Migration
  def up
    execute "UPDATE table_name SET type = 'Namespace::NewSubclass' WHERE type = 'Namespace::OldSubclass'"
  end

  def down
    execute "UPDATE table_name SET type = 'Namespace::OldSubclass' WHERE type = 'Namespace::NewSubclass'"
  end
end