Getting the average of not null fields <p>I'm using Crystal reports in my application </p> <pre><code>average({ConsultationDetail.viandenord} ) </code></pre> <p>I need to get the avearge of not null field <code>viandenord</code> </p> <ol> <li>How can i change the formula to get this result?</li> <li>What is the best way to do that?</li> </ol>