Multiple dataset integration

Hi.. i am using jasperstudio 6.6.0

I need to create a report that retrieve datas from a postgres database using as source filter a csv file.

so I made two dataset, the first which have as source the db connection (dataset1), and the second which have as source the xml dateset created by reading the csv file (dataset2)..

what i need is to have a query like this:

"select d2.*,d1.* from <dataset2>as d2 join <dataset1.mytable> as d1 on d1.id=d2.id"

Now how can i refer the dataset directly in the sql quuery, or how can i pass the value throught params/variables?

thanks..