多行数据合成一行

SELECT DISTINCT customer_order_no, customer_item_no, customer_name_full OVER (PARTITION BY customer_order_no, customer_item_no) AS customer_name
           FROM (SELECT customer_order_no, customer_item_no, SYS_CONNECT_BY_PATH (customer_name, ',') customer_name_full FROM (
                                  SELECT customer_order_no, customer_item_no, customer_name, LAG(customer_name, 1, '') OVER (PARTITION BY customer_order_no, customer_item_no ORDER BY customer_name) customer_name_1
                                    FROM (
                                         SELECT t.customer_order_no, t.customer_item_no,t.customer_name FROM tourism_hotel_order_customer t where t.customer_order_no = '20081230R007' and t.customer_item_no = '01'
                                         ))  CONNECT BY  PRIOR customer_name =  customer_name_1 ORDER BY customer_order_no, customer_item_no)