problem :pie chart (Key is null)

[masdar]

i use iReport 3.5.2

in my report i have the query:

    SELECT     BTCS.OTA    AS OTA,
             count(*) AS counter
        FROM
              BTCS
        GROUP BY     BTCS.OTA

which executed successfully

this query return 2 values

OTA                  java.lang.String

COUNTER              Java.lang.BigDecimal

i inserted a pie chart in Summary section

the chart has the follows values

Dataset->

            Reset type : Report

            Increment type:None

Details->

                    Section value->

                             Key expression:    $F{OTA}

                           Value expression: $F{COUNTER}

                           Label expression: $F{OTA}

---------------------------------------------------------------------------------------

in compiling there is not problem

but  when i preview the report i get an error

Error filling print... Key is null in pie dataset.
net.sf.jasperreports.engine.JRRuntimeException: Key is null in pie dataset. 
    at net.sf.jasperreports.charts.fill.JRFillPieDataset.customIncrement(JRFillPieDataset.java:263) 
    at net.sf.jasperreports.engine.fill.JRFillElementDataset.increment(JRFillElementDataset.java:179) 
    at net.sf.jasperreports.engine.fill.JRCalculator.calculateVariables(JRCalculator.java:152) 
    at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:716) 
    at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportContent(JRVerticalFiller.java:276) 
    at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:118) 
    at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:911) 
    at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:814) 
    at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:63) 
    at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:421) 
    at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:251) 
    at com.jaspersoft.ireport.designer.compiler.IReportCompiler.run(IReportCompiler.java:898) 
    at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561) 
    at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986) 

 

Post Edited by masdar at 09/08/2009 12:47

[kchaudhry]

The problem is that your query is returning a null for $F{OTA} and therefore you are getting this error message. You can modify your query to exclude nulls for this field and that will resolve the issue. The reason why you don't get any error message at compliation time is due to the fact that the issue is with the data and not the report.

Hope this helps!

[masdar]

Thank you alot,, i'll try that,