Rails: validate unique combination of 2 columns

Question

leave_policy is table having columns :id ,:group_detail_id , employee_type_id,

I want to combination of :group_detail_id and employee_type_id should not be duplicate.

validates_uniqueness_of :employee_type_id ,:scope => :group_detail_id

this line is not working...I don't know why?????

Answer 1

Try:

validate :unique_combination

def unique_combination
  self.class.exists?(
    :employee_type_id => employee_type_id,
    :group_detail_id => group_detail_id
  )
end