How to return all Models if id is nil in Rails?

Question

Ruby on Rails

How to return all Models if id is nil in Rails ?

arr_id = [1, 2, 3]

Model.where(id: arr_id)

For example, if here arr_id is nil or an empty array, then how to remove this Where check ?

Answer 1

def self.filter_id(arr_id)
  if arr_id.present?
    where(id: arr_id)
  else
    all
  end
end

or

scope :filter_id, -> arr_id { where(id: arr_id) if arr_id.present? }

Answer 2

if arr_id.nil? || arr_id.empty?
  Model.all
else
  Model.where id: arr_id
end