Chọn truy vấn con trả về nhiều hàng dưới dạng chuỗi (một cột) trong bảng (Oracle SQL)

SQL Fiddle

Thiết lập lược đồ Oracle 11g R2 :

CREATE TABLE Product ( Product_No, Column1, Column2 ) AS
SELECT 1, 'A', 10 FROM DUAL UNION ALL
SELECT 2, 'B', 11 FROM DUAL UNION ALL
SELECT 3, 'C', 12 FROM DUAL
/
CREATE TABLE Inventory ( Product_No, Inventory_No, ColumnA, ColumnB, ColumnC ) AS
SELECT 1, 1, 'ABC',  20,  30 FROM DUAL UNION ALL
SELECT 1, 2, 'DDD',  30,  50 FROM DUAL UNION ALL
SELECT 2, 1, 'EFG',  60,  70 FROM DUAL UNION ALL
SELECT 2, 2, 'CDE',  99, 100 FROM DUAL UNION ALL
SELECT 3, 3, 'EFF', 120,  30 FROM DUAL
/

Truy vấn 1 :

SELECT p.*, i.ColumnX
FROM   Product p
       LEFT OUTER JOIN
       ( SELECT Product_no,
                LISTAGG(
                  ColumnA || '-' || ColumnB || '-' || ColumnC,
                  ','
                ) WITHIN GROUP ( ORDER BY Inventory_no )
                AS ColumnX
         FROM   Inventory
         GROUP BY Product_No
       ) i
       ON ( p.product_no = i.product_no )

Kết quả :

| PRODUCT_NO | COLUMN1 | COLUMN2 |              COLUMNX |
|------------|---------|---------|----------------------|
|          1 |       A |      10 |  ABC-20-30,DDD-30-50 |
|          2 |       B |      11 | EFG-60-70,CDE-99-100 |
|          3 |       C |      12 |           EFF-120-30 |