title: Unknown column name issue
body: <p>I'm creating a JasperReports's report using some database connection using iReport. I have added a new field to the report. That field does not exist in the database column. I have put that column in the report and assigning the value to this field using the expression.</p>
  
  <p>It compiles fine but when I fill the report using the database, it gives me the error: </p>
  
  <pre><code>Error filling print... Unknown column name : test 
  net.sf.jasperreports.engine.JRException: Unknown column name : test
  at net.sf.jasperreports.engine.JRResultSetDataSource.getColumnIndex(JRResultSetDataSource.java:355) 
  at net.sf.jasperreports.engine.JRResultSetDataSource.getFieldValue(JRResultSetDataSource.java:112)  
  at net.sf.jasperreports.engine.fill.JRFillDataset.setOldValues(JRFillDataset.java:823)  
  at net.sf.jasperreports.engine.fill.JRFillDataset.next(JRFillDataset.java:787)
  at net.sf.jasperreports.engine.fill.JRBaseFiller.next(JRBaseFiller.java:1474)  
  at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:125) 
  at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:938)  
  at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:841)  
  at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:58)  
  at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:417)  
  at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:247)  
  at com.jaspersoft.ireport.designer.compiler.IReportCompiler.run(IReportCompiler.java:858)
  at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)  
  at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)  
  Print not filled. Try to use an EmptyDataSource...
  </code></pre>
  
  <p>How can I use the user defined fields in JasperReports?</p>