How to use print when expression for no rows

[ktalarico]

What is the correct expression to enter when I want an element to appear only when the number of rows returned from my SQL query is zero?

[jmurray]

The Print When expression you would use is something like this:

 

 

new java.lang.Boolean($V{REPORT_COUNT}.intValue()==0)

 

 

But be careful: the value of REPORT_COUNT is not available until AFTER the detail section has been filled. That means that you can normally only use that expression in a footer or summary section.

 

 

There is a way around the problem though. You can use a subquery to return the value BEFORE the detail section is filled because subreports are always filled first. The subreport doesn't need to display anything, it just returns the value of REPORT_COUNT so that you can store it in your own variable within the main report. The subreport's query is the same as the query in the main report.

 

 

The best place to put it is in a header section, out of the way. Once your variable has the value of REPORT_COUNT from the subreport you can use it in any subsequent band, including the Detail band. The expression now has to refer to your own variable:

 

 

new java.lang.Boolean($V{yourVariable}.intValue()==0)

[ktalarico]

Thank you very much. I'm having problems getting my element to print. Can you tell me if I need to modify my destination variable for the REPORT_COUNT in a specific way? (i.e., Calculation Type, Reset Type, Increment Type, etc.)

[ktalarico]

I'm all set now with the help of some of your other posts. Thanks again.