How to add variable from subdataset to report? [Jasper]

问题

I have sub Dataset that include a calculated variable that I want to show in the report. But when dragging and dropping this variable into the report the following message appears:

You drop an object from a subdataset to the report, this is not possible.

How to overcome that?

回答1:

There is a solution which is already posted at - Solution-1

However, I am posting a set of screenshots to demonstrate the same from UI -

1. Define var in the main data set - Note - Calculation should be set to System
2. Define another variable in the sub data set -
3. Select the sub data set element ( it is a table in the example) and create Return Values mapping -
4. In the report, drag and drop variable defined in the main data set and ensure the evaluation is set to Report -

And that should do it!!

来源：https://stackoverflow.com/questions/58181821/how-to-add-variable-from-subdataset-to-report-jasper