destroy

# File activerecord/lib/active_record/locking/optimistic.rb, line 102
        def destroy #:nodoc:
          return super unless locking_enabled?

          destroy_associations

          if persisted?
            table = self.class.arel_table
            lock_col = self.class.locking_column
            predicate = table[self.class.primary_key].eq(id).
              and(table[lock_col].eq(send(lock_col).to_i))

            affected_rows = self.class.unscoped.where(predicate).delete_all

            unless affected_rows == 1
              raise ActiveRecord::StaleObjectError.new(self, "destroy")
            end
          end

          @destroyed = true
          freeze
        end