title: optional where clause jasper reports
body: <p>I am trying this query but without success.</p>
  
  <pre><code>SELECT name, phone_office, billing_address_city, billing_address_street, billing_address_country 
  FROM accounts
  WHERE ($P!{EmployeeID} is null or assigned_user_id = $P!{EmployeeID})
  ORDER BY billing_address_country, billing_address_city
  </code></pre>
  
  <p>This url will filter by EmployeeID and works fine:</p>
  
  <pre><code>.../flow.html?_flowId=viewReportFlow&amp;reportUnit=/reports/samples/EmployeeAccounts&amp;EmployeeID=sarah_id
  </code></pre>
  
  <p>But when i remove the EmployeeID parameter i want to remove the filter where. So all results should be shown.</p>
  
  <pre><code>.../flow.html?_flowId=viewReportFlow&amp;reportUnit=/reports/samples/EmployeeAccounts
  </code></pre>
  
  <p>My question is, what is the correct way of passing an optional where in sql query.</p>