title: SQLAlchemy substring is in string
body: <p>I am trying to query a database for records that have a string field inside an input search string. </p>
  
  <p>Something like this:</p>
  
  <pre><code>User.query.filter(User.name in search_string)
  </code></pre>
  
  <p>Of course that does not work since it is not a valid SQLAlchemy statement.
  This seems a simple problem but I really can't find the right column operator. </p>
  
  <p>I tried the <code>in_</code> operator:</p>
  
  <pre><code>User.query.filter(User.name.in_(search_string)
  </code></pre>
  
  <p>But that of course is not working. What I need is a <code>is_substring</code> operator.</p>