title: JRValidationException: Report design not valid
body: <p>I have a MySQL database named <strong>test-3</strong> and only one table named <strong>student</strong>. The table structure is like this:</p>
  
  <pre><code>CREATE TABLE `student` (
  `student_id` int(11) NOT NULL AUTO_INCREMENT,
  `student_name` varchar(50) NOT NULL,
  `nationality` varchar(255) NOT NULL,
  `department` varchar(30) NOT NULL,
  `fathers_name` varchar(50) DEFAULT NULL,
  `mothers_name` varchar(50) DEFAULT NULL,
   PRIMARY KEY (`student_id`)
   ) 
  </code></pre>
  
  <p>So now, I want to create a report in iReport 5.5.0, I right-clicked on my report name, selected the option <em>Add Dataset</em>,  then created a new datasource and named it as <strong>data</strong>. I selected MySQL from the dropdown list, selected the database, made the MySQL connection and it went successful. So far, so good. Now, I have designed my report structure previously, and I have also dragged the table into my report using the drag-and-drop option in iReport (selecting field from the dataset and then drag-and-drop into the report). But whenever I click the <em>Preview</em> button, I get the following message:</p>
  
  <pre><code> net.sf.jasperreports.engine.design.JRValidationException: Report design not valid :       
   1. Field not found : student_name      
   2. Field not found : nationality      
   3. Field not found : department
  </code></pre>
  
  <p>And my report is not loaded. </p>
  
  <p>The SQL Query I ran to retrieve the resultset was this:</p>
  
  <pre><code>  select student_name, nationality, department 
    from student
  </code></pre>
  
  <p>Can anyone please explain where the problem is? I am absolutely a newby to JasperReports and iReport.</p>