@Override
 public boolean visitSelect(EJBQLExpression expression) {
   // this ensures that result columns are appeneded only in top-level select, but
   // not subselect (as 'visitSelect' is not called on subselect)
   context.setAppendingResultColumns(true);
   return true;
 }
 @Override
 public boolean visitFrom(EJBQLExpression expression, int finishedChildIndex) {
   context.append(" FROM");
   context.setAppendingResultColumns(false);
   expression.visit(context.getTranslatorFactory().getFromTranslator(context));
   context.markCurrentPosition(context.makeWhereMarker());
   context.markCurrentPosition(context.makeEntityQualifierMarker());
   return false;
 }