Sending SQL query to Crystal Reports

Hi All,
I am pretty new to working with Crystal reports and ASp.NET. I am developing an application that constructs a "Adhoc" sql query and displays a PDF file showing the records.
I was wondering if there is a way I can send the SQL query as the datasource to my Crystal report. PLease note that the size of the database I am working on is really huge and the Query I generate can produce results that can run into hundereds of pages.
I there is there a way I can do all these in the Crystal reports? The probelms is the number of the columns that a query can have varies all the time.
Any pointers or advice is really appreciated.

Thanks in Advance
Bala