# File lib/symetrie_com/acts_as_better_nested_set.rb, line 333
          def sql_for(items)
            items = [items] unless items.is_a?(Array)
            # get objects for IDs
            items.collect! {|s| s.is_a?(acts_as_nested_set_options[:class]) ? s : acts_as_nested_set_options[:class].find(s)}.uniq
            items.reject! {|e| e.new_record?} # exclude unsaved items, since they don't have left/right values yet
          
            return "1 != 1" if items.empty? # PostgreSQL didn't like '0', and SQLite3 didn't like 'FALSE'
            items.map! {|e| "(#{prefixed_left_col_name} BETWEEN #{e[left_col_name]} AND #{e[right_col_name]})" }
            "(#{items.join(' OR ')})"
          end