title: How to check if a Django arrayfield has data
body: <p>I have a Django model for articles with an array field that sometimes has ids. </p>
  
  <pre><code>id_list = ArrayField(models.CharField(max_length=10000), blank=True, null=True)
  </code></pre>
  
  <p>I want to write a query that finds all the article objects that have data in the id_list. I tried the following, but it did not work.</p>
  
  <pre><code>Article.objects.filter(id_list__isnull=False)
  </code></pre>
  
  <p>What is the correct way to write this? Thank you.</p>