title: Spring Data mongo case insensitive like query
body: <p>I want to make a text search case insensitive with regex query with <code>spring-data mongo </code>.</p>
  
  <p>For example in Oracle :</p>
  
  <p><code> select * from user where lower(username) like '%ab%' </code></p>
  
  <p>How can i make this query  with <code>spring-data mongo </code>?</p>
  
  <p>Thanks in advance</p>