Duplicate data in jasper

Question

I have very simple select query in my dataset and Query dialog. When I run this query I get 2 times more data fields as there are in the database! And my report boo

Answer 1

The problem is not because of the driver or source code. It happens when I add a report books. Then the wave book asks for a data source and query. When I write a query there, jasper adds those results to the ones from main report.