title: How to update all my text _id field from "abc" to "xxx#abc" in MongoDB
body: <p>I have a collection where the <code>_id</code> is a Text field. I need to update this field by adding a prefix to it like <strong>xxx#</strong>, so if a field value was "<strong>abc</strong>" it's must be now "<strong>xxx#abc</strong>"</p>
  
  <p>How can I do that with MongoDB?</p>