title: How to translate INSERT INTO ... SELECT to MongoDB
body: <p>I would like to know what's the equivalent of this MySQL command in MongoDB.</p>
  
  <pre><code>INSERT INTO xyz (field1, field2, field3, field4)
  SELECT t1.id, t2.id, t3.id, NOW() FROM t1, t2, t3
  </code></pre>
  
  <p>I've been using MongoDB for only 48 hours and I'm afraid I just can't figure that one out.</p>
  
  <p>Thanks for everything :).</p>