title: Grails gorm 'where' query with 'lower()' and 'in' operator
body: <p>I have a Domain class</p>
  
  <pre><code>class Hashtag {
      String tag
  }
  </code></pre>
  
  <p>Why</p>
  
  <pre><code>Hashtag.where { lower(tag) == "#london" }.list()
  </code></pre>
  
  <p>works ok, but</p>
  
  <pre><code>Hashtag.where { lower(tag) in [ "#london", "#paris" ] }.list()
  </code></pre>
  
  <p>results in</p>
  
  <p><code>org.springframework.dao.InvalidDataAccessResourceUsageException: Unsupported function [lower] defined in query for property [hashtag] with type [class java.lang.String]</code></p>
  
  <p>How to write such query properly?</p>
  
  <p>Thanks!</p>