title: How to check if predicate expression was changed?
body: <pre><code> var predicate = PredicateBuilder.True&lt;o_order&gt;();
  </code></pre>
  
  <p>This is my predicate expression, where on some certain conditions I will append expressions with it.</p>
  
  <p><strong>Likewise</strong></p>
  
  <pre><code> if (!string.IsNullOrEmpty(param.sSearch))
                  predicate = predicate.And(s =&gt; s.OrderID.ToString().Contains(param.sSearch));
  </code></pre>
  
  <p>Now my question is if this expression doesn't pass by this condition then would there be any expression? and how would I know if it returns no expression with it.</p>
  
  <p>Simply I want to do-</p>
  
  <p><code>if(predicate==null)</code> or <code>if(predicate contains no expression)</code></p>