columns_for_remove

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 593
        def columns_for_remove(table_name, *column_names)
          column_names = column_names.flatten

          raise ArgumentError.new("You must specify at least one column name. Example: remove_column(:people, :first_name)") if column_names.blank?
          column_names.map {|column_name| quote_column_name(column_name) }
        end