public void testDistinct() throws JSQLParserException {
   String statement = "SELECT DISTINCT ON (myid) myid, mycol FROM mytable WHERE mytable.col = 9";
   PlainSelect plainSelect =
       (PlainSelect) ((Select) parserManager.parse(new StringReader(statement))).getSelectBody();
   assertEquals(
       "myid",
       ((Column)
               ((SelectExpressionItem) plainSelect.getDistinct().getOnSelectItems().get(0))
                   .getExpression())
           .getColumnName());
   assertEquals(
       "mycol",
       ((Column) ((SelectExpressionItem) plainSelect.getSelectItems().get(1)).getExpression())
           .getColumnName());
   assertEquals(statement.toUpperCase(), plainSelect.toString().toUpperCase());
 }