title: Amazon RDS MySQL only_full_group_by
body: <p>I recently upgraded to MySQL v5.7 from v5.6 on RDS.</p>
  
  <p>Now I sometimes get the error:</p>
  
  <pre><code> Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'USER.t.training_team_id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
  </code></pre>
  
  <p>I checked my config with SELECT @@GLOBAL.sql_mode and only get:</p>
  
  <pre><code> NO_ENGINE_SUBSTITUTION
  </code></pre>
  
  <p>However this still happens.</p>
  
  <p>The weird part is, that it only happens sometimes. I cannot force it to happen and I can't seem to disable the only_full_group_by option.</p>
  
  <p>How do I change this?</p>