build_insert_sql

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 504
      def build_insert_sql(insert) # :nodoc:
        sql = +"INSERT #{insert.into} #{insert.values_list}"

        if insert.skip_duplicates?
          no_op_column = quote_column_name(insert.keys.first)
          sql << " ON DUPLICATE KEY UPDATE #{no_op_column}=#{no_op_column}"
        elsif insert.update_duplicates?
          sql << " ON DUPLICATE KEY UPDATE "
          sql << insert.updatable_columns.map { |column| "#{column}=VALUES(#{column})" }.join(",")
        end

        sql
      end