title: Storing and querying JSON from a database
body: <p>I've heard about MongoDB, but I'm not sure I fully understand the concept. </p>
  
  <p>If I have multiple JSON objects stored in MongoDB:</p>
  
  <pre><code>[{"id": "peter",
    "age": "12",
    "gender": "male"},
   {"id": "gemma",
    "age": "12",
    "gender": "female"},
   {"id": "paul",
    "age": "13",
    "gender": "male"}]
  </code></pre>
  
  <p>How would I be able to query all JSON objects with <code>age &gt;= 12</code>?</p>