JOIN別名不存在並且不正確地結束

Question

如this線程中所述，from子句中的子查詢不是必需的，並且會產生笛卡爾積，但會出現新問題。

SELECT customer.customer_name 
     ,orders.order_date 
     ,order_line.num_ordered 
     ,order_line.quoted_price 
     ,part.descript 
     ,amt_billed 
FROM (SELECT order_line.num_ordered*part.price AS amt_billed 
      FROM order_line 
      JOIN part 
      ON order_line.part_num = part.part_num 
     ) billed 
      ,customer 
     JOIN orders 
     ON customer.customer_num = orders.customer_num 
     JOIN order_line 
     ON orders.order_num = order_line.order_num 
     JOIN part 
     ON order_line.part_num = part.part_num; 

讓我們說我決定在from子句中使用子查詢。如果您閱讀了註釋，@JorgeCampos建議我使用AS來建立別名，然後在子查詢和現有表之間編寫連接。

當我在子查詢和別名billed之間放置AS時，我得到一個ORA-00933: SQL command not properly ended。刪除AS並運行它不會返回錯誤，而是笛卡爾產品。

此外，我嘗試使用billed別名返回ORA-00942: table or view does not exist。

以供參考，在這裏是ERD整個數據庫：

最後，我想知道如何，如果我下定決心要保持子查詢在FROM子句中，這將被寫入。

我正在使用Oracle 11g pl/sql。

更新

此：

SELECT customer.customer_name 
     ,orders.order_date 
     ,order_line.num_ordered 
     ,order_line.quoted_price 
     ,part.descript 
     ,amt_billed 
FROM (SELECT order_line.num_ordered*part.price AS amt_billed, orders.order_num 
     FROM order_line 
     JOIN part 
      ON order_line.part_num = part.part_num 
      ) AS billed 
    JOIN customer 
     ON customer.customer_num = orders.customer_num 
    JOIN billed 
     ON orders.order_num = order_line.order_num 
    JOIN orders 
     ON customer.customer_num = orders.customer_num 
    JOIN order_line 
     ON orders.order_num = order_line.order_num 
    JOIN part 
     ON order_line.part_num = part.part_num; 

返回此：

 ) AS billed 
     * 
ERROR at line 11: 
ORA-00933: SQL command not properly ended 

在行刪除AS 11返回此：

JOIN billed 
    * 
ERROR at line 14: 
ORA-00942: table or view does not exist 

更新

感謝@GordonLinoff，我呈現給你的最終代碼！

SELECT customer.customer_name 
     ,orders.order_date 
     ,order_line.num_ordered 
     ,order_line.quoted_price 
     ,amt_billed 
     ,part.descript 
    FROM customer 
    JOIN orders 
     ON customer.customer_num = orders.customer_num 
    JOIN order_line 
     ON orders.order_num = order_line.order_num 
    JOIN part 
     ON order_line.part_num = part.part_num 
    JOIN (SELECT DISTINCT order_line.part_num 
          ,order_line.num_ordered*part.price AS amt_billed 
      FROM order_line 
      JOIN part 
       ON order_line.part_num = part.part_num 
     ) billed 
     ON billed.part_num = order_line.part_num 
ORDER BY customer.customer_name, orders.order_date; 

我照他說的去做了，並且刪除了給客戶的冗餘連接。我也不得不將這些子選擇加入進來。如果我堅持num_ordered，那麼只要訂購了一個零件，行就會重複它們自己。

Answer 1

對於表別名，Oracle不支持as。所以：

FROM (SELECT order_line.num_ordered*part.price AS amt_billed, orders.order_num 
     FROM order_line JOIN 
      part 
      ON order_line.part_num = part.part_num 
    ) billed JOIN 
--------^ 
     Customer 
     . . . 

編輯：

你不需要重複billed。你想這樣的事情：

FROM customer JOIN 
    orders 
    ON customer.customer_num = orders.customer_num JOIN 
    order_line 
    ON orders.order_num = order_line.order_num JOIN 
    part 
    ON order_line.part_num = part.part_num JOIN 
    (SELECT order_line.order_num, order_line.num_ordered*part.price AS amt_billed 
     FROM order_line JOIN 
      part 
      ON order_line.part_num = part.part_num 
    ) billed 
    ON billed.order_num = order.order_num;