I know this thread is a bit old, but I'm facing the same issue here. I'm new to Jasper Reports but I've noticed it's very similar to BIRT which is what we are migrating from. In any case, I wanted to ask about your instructions to join a subquery parameter to the main report's parameter, particularly the instruction " right click on the List (or Table, I presume) component in the Report Inspector Tree and choose "Edit List Datasource". I'm using iReport 4.7.0 and for the life of me I can't find a List item on the report tree. Could this just be an issue with iReport versions? Again, I apologize for re-opening the thread but I can't seem any light on this subject.