title: Why Yii2 is down with try/catch?
body: <p>I insert an entry in which there is a duplicate of the primary key.</p>
  
  <pre><code>public function actionInc()
  {
          $add = new Country();
          $add-&gt;code = 'QI';
          $add-&gt;name = 'Qiang';
          $add-&gt;population = '4444444';
      try {
          $add-&gt;save();
          return $this-&gt;render('inc', [
              'count' =&gt; 'Ok',
          ]);
      } catch (Exception $exception) {
          return $this-&gt;render('inc', [
              'count' =&gt; 'Error',
          ]);
      }
  }
  </code></pre>
  
  <p>But I need that the application does not down, and continued to work, but it does not work...
  <img src="https://i.stack.imgur.com/M6TtF.jpg" alt="screenshot"></p>