[Zope] how to get next iteration values?

Hi, does somebody knows how to get next iterations of columns from SQL query? I think that is only due my unknowledge of right pythonic syntax. <dtml-let vypisSQL_LET="vypisSQL()"> -- ZSQL method results catch <dtml-in vypisSQL_LET prefix="listing"> current value: <dtml-var column> next value: <dtml-var "vypisSQL_LET.column[listing_number]"> -- here is an error </dtml-in> </dtml-let> Do you have some ideas how to get next value, please? It is possible to do with fill ['','',''....] fields or with memorizing/display last values as a main result, but it is not what I want, it is quite large sequence and ### columns. Many thanks, JL.