how to handle dynamic result

Hi, 

I want to create a customer-search screen which have a bunch of criteria. users can pick some criteria to do search, in the backend, I build a query base on what fields the user choose and return them to the result page.  but the problem is the resultset is dynamic as number of columns changes from time to time.   What is the best way to implement the dataset?  as I'm assuming we always need dataset in order to return data to webpage.

 Thanks

 
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