yii1.1: $model->save() failed, but $model->getErrors() return empty array
<p>I'm using YII1.1.16, I have some code like this:</p>

<pre><code>public function actionAdd()
{
    $article = new Article;
    $article-&gt;type = $this-&gt;type;

    if (isset($_POST['article'])) {
        $article-&gt;attributes = $_POST['article'];
        if ($article-&gt;save()) {
            $this-&gt;success('saved');
        } else {
            var_dump($article-&gt;getErrors());
        }
    }

    $this-&gt;render('add');
}
</code></pre>

<p>but, now the <code>save()</code> failed, but <code>getErrors()</code> return empty array(), so how can I know why it failed when saving the record?</p>