MySQL的查詢 - 如何計數與第三表連接的第二個表的外鍵發生？

Question

這裏是我的數據樣本：

 
product 
-------------------------------- 
| product_id PK | product_name | 
-------------------------------- 
| FRT1   | Apple  | 
| FRT2   | Orange  | 
| TXT1   | Ribbon  | 
-------------------------------- 

package 
------------------------- 
| package_id PK | price | 
------------------------- 
| P001   | 1000 | 
| P002   | 1500 | 
| P003   | 1000 | 
------------------------- 

package_detail 
--------------------------------- 
| package_id FK | product_id FK | 
--------------------------------- 
| P001   | FRT1   | 
| P002   | FRT1   | 
| P002   | FRT2   | 
| P003   | FRT2   | 
--------------------------------- 

用於搜索的關鍵是PRODUCT_NAME，所以如果我搜索「蘋果」，結果應該是這樣的：

 
------------------------------------------- 
| package_id | price | num_of_package_dtl | 
------------------------------------------- 
| P001  | 1000 | 1     | 
| P002  | 1500 | 2     | 
------------------------------------------- 

我在加入弱，任何人幫助我的查詢？ 預先感謝您〜

Answer 1

SELECT b.package_id, c.price, d.totalCount 
FROM product a 
     INNER JOIN package_detail b 
      ON a.product_ID = b.product_ID 
     INNER JOIN package c 
      ON b.package_ID = c.package_ID 
     INNER JOIN 
     (
      SELECT package_id, COUNT(*) totalCount 
      FROM package_detail 
      GROUP BY package_id 
     ) d ON d.package_ID = b.package_ID 
WHERE a.product_name = 'apple' 

SQLFiddle Demo

Answer 2

事情是這樣的：

選擇pd.package_id，p.price，COUNT（*）從package_detail PD num_of_package_dtl頁上加入包頁。 package_id = pd.package_id加入產品pt.product_id = pd.product_id其中pd.product_name ='Apple'組通過pd.package_id，p.price