A class with a proc scope

scope.rb

class User < ActiveRecord::Base
  
  scope :hello_lamb, ->(param) { param.blank? ? where("") : where("param = ?", param) }
  scope :hello_proc, Proc.new { |param| param.blank? ? where("") : where("param = ?", param) }
  
end

User.hello_lamb "a"
#  User Load (0.5ms)  SELECT * FROM users WHERE  (param = 'a') 
#=> #<ActiveRecord::Relation:0x3fe6eedeb984>

User.hello_proc "a"
#  User Load (0.5ms)  SELECT * FROM users WHERE  (param = 'a') 
#=> #<ActiveRecord::Relation:0x3fe6eedeb984>

User.hello_lamb ""
#  User Load (0.5ms)  SELECT * FROM users
#=> #<ActiveRecord::Relation:0x3fe6eedeb984>

User.hello_proc ""
#  User Load (0.5ms)  SELECT * FROM users
#=> #<ActiveRecord::Relation:0x3fe6eedeb984>