0
我想獲得一個所有我類標識碼查詢之後的PRODUCT_ID:如何進一步子查詢從SQL查詢中獲取所有Product_ID?
SELECT * FROM tbl_Categories WHERE Class_ID = 1
-------------tbl_Categories------------------
| Category_ID | Class_ID | Product_ID |
| 1 | 1 | 2 |
| 2 | 1 | 3 |
| 3 | 4 | 4 |
| 1 | 1 | 1 |
應返回我1,2,3
我如何查詢呢?