title: How make select as with mongoose
body: <p>I have this Track Schema  <code>{&quot;_id&quot;: '123', &quot;external_id&quot;: 'abc', &quot;name&quot;: 'make work'}</code> and I have queryng <code>external_id</code> as songId and <code>name</code> as songTitle. How make this?</p>