Shortcut for getting ids for an ActiveRecord scope
You can use .ids on an ActiveRecord 4+ scope to pluck all the ids of the relation
User.where("users.name LIKE 'Foo Bar'").ids
# same as (since Rails 3.2)
User.where("users.name LIKE 'Foo Bar'").pluck(:id)
If you are stuck on Rails 2.3 you can use
Edge Rider's collect_ids
Show archive.org snapshot
:
User.where("users.name LIKE 'Foo Bar'").collect_ids(:id)