ruby - Rails get objects in front of dot of a class method -

students = student.limit(3) students.approve()  def self.approve     # ... end 

i want students , use each_with_index, fails. tried self, points out

"nomethoderror: undefined method `each_with_index' #<class:0x00000007a1b920>". 

i want objects in front of method, how can this, !

in approve method have activerecord::relation, need array instead:

def self.approve_all   all.each_with_index |user, index|     ...   end end 

class methods in activerecord models can called not on class itself, on activerecord::relation objects.

so example, can call .approve_all method not directly on class: student.approve_all, on relation student class: student.order(name: :asc).limit(10).where(state: "not_approved").approve_all

but think method should @ least named update_all, , try figure out better solution problem.