return aggregateExpr;
    }
    public SQLOrderBy parseOrderBy() {
        if (lexer.token() == Token.ORDER) {
            SQLOrderBy orderBy = new SQLOrderBy();
            lexer.nextToken();
            accept(Token.BY);
            orderBy.getItems().add(parseSelectOrderByItem());
            while (lexer.token() == Token.COMMA) {
                lexer.nextToken();
                orderBy.getItems().add(parseSelectOrderByItem());
            }
            return orderBy;
        }