JasperReport: Purpose of the Details Band

Question

I figured this would be something that would be fairly-well documented as its a central theme to JasperReports, however I can\'t find an answer for this anywhere.

Answer 1

As I remember it, you can see the details band as the "model" for a row/record in the report. All elements you put inside the detail band will be repeated for each record provided by the JRDatasource.

For example, your details band might have two text fields, one with the value ${companyName}, and one with the value value ${revenue}.

If you now pass your report three rows, then "companyName" and "revenue" will be evaluated for each of them, and you may get something like:

|Apple              |  $1000,000,000|
|Microsoft          |   $500,000,000|
|My amazing company |            $12|

I.e., the detail band contents has been repeated three times.

So: - As you see you probably only need one details band configured. Not sure if it's allowed in the JRXML to have multiple ones. - There is no relationship between the details band and a page. Pagination is handled separately. - Not sure, to be honest. My best guess is either an exception or you get no rows where the detail band is supposed to be rendered.