title: SQL Update If value = 1
body: <p>I have a SQL "ON DUPLICATE KEY UPDATE".  In that section of the update I have multiple fields.  One of the fields is active.  What I am trying to do is only update the active field if the current value is 1. I've know how to update if ISNULL: <code>active = ISNULL(@active, active)</code>.  Is there a way to do the same thing if the value is 1?</p>
  
  <pre><code>ON DUPLICATE KEY UPDATE 
                            display_name=VALUES(display_name),
                            wholesale=VALUES(wholesale),
                            saleWS=VALUES(saleWS),
                            taxable=VALUES(taxable),
                            sku=VALUES(sku),
                            code=VALUES(code),
                            onSale=VALUES(onSale),
                            description=VALUES(description),
                            link=VALUES(link),
                            image=VALUES(image),
                            display_page=VALUES(display_page),
                            attachment=VALUES(attachment),
                            applyCoupon=VALUES(applyCoupon)
  </code></pre>