Rails Pluck

• if you only need the id with Rails 4, use ids: User.first.gifts.ids
• if you only need some fields with Rails 4, use pluck: User.first.gifts.pluck(:id, :name, ...)
• if you only need one field with Rails 3, use pluck: User.first.gifts.pluck(:id)
• if you need all fields, use collect
• if you need some fields with Rails 4, still use pluck
• if you need some fields with Rails 3, use selectand collect