title: MongoDB - Contains (LIKE) query on concatenated field
body: <p>I am new in MongoDB.</p>
  
  <p>I am programming an application with spring data and mongodb and I have one class with two fields: <code>firstname</code> and <code>lastname</code>.</p>
  
  <p>I need one query for documents that contain one string in the full name (<code>firstname</code> + <code>lastname</code>). </p>
  
  <p>For example: <code>firstname = "Hansen David"</code>, <code>lastname = "Gonzalez Sastoque"</code> and I have a query to find <code>David Gonzalez</code>. In this example I expect there to be a match.</p>
  
  <p>Concatenate two strings solves it but I don't know how to perform this.</p>