title: Firestore query document's field ID
body: <p>I'm trying to do my query filtering for field id. I want to return all documents that contains a field id, and then it's value.</p>
  <p><a href="https://i.stack.imgur.com/IqT7Z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IqT7Z.png" alt="enter image description here" /></a></p>
  <p>In this example I want to do something like:</p>
  <pre><code>db.collection(&quot;assistencia&quot;).where(&quot;&gt;&gt;&gt; 0qSzBxVimwRlurLHNzXp EXIST &lt;&lt;&lt;&lt;&quot;) &lt;=== I don't know what I need to put here
  .get()
  .then(function(querySnapshot) {
      querySnapshot.forEach(function(doc) {
          // doc.data() is never undefined for query doc snapshots
          console.log(doc.id, &quot; =&gt; &quot;, doc.data());
      });
  })
  </code></pre>
  <p>Any suggestion?</p>