title: Use listAgg with H2 db in Grails
body: <p>I have a grails application. We support Oracle db and H2 db.</p>
  
  <p>I'm using Oracle 11g DB on prod and H2 DB on dev environment.
  I have hibernate query with "listAgg" function. It works fine on Oracle.
  But H2 doesn't support this function. What can I do to use this function with H2 also?</p>
  
  <p>I think it can be done through custom dialect. But I do not understand how. Can anyone explain in detail?</p>
  
  <p>I see H2 has 'group_concat' function that is similar to listAgg. Can I configure my application so that the 'group_concat' used for H2DB instead of listAgg. </p>
  
  <p>Grails 2.3.11.</p>
  
  <p>Thanks a lot!</p>