MYSQL - 查找重複交叉關係表

Question

我有三個表：

`products` 
---------- 
`product_id` (int) 
`sku` (varchar=50) 

`websites` 
---------- 
`website_id` (int) 

`website_products` 
---------- 
`website_id` (int) 
`product_id` (int) 

我試圖找到複製基礎上，每個SKU網站產品。這是我迄今的嘗試，但很確定它不工作：

SELECT b.`website_id`, a.`product_id` ,COUNT(a.*) AS count 
FROM `products` AS a 
    LEFT JOIN `website_products` AS b 
     ON (a.`product_id` = b.`product_id`) 
WHERE 1 
GROUP BY a.`sku` 
HAVING count > 1 
ORDER BY b.`website_id` 

任何人有什麼想法？

Answer 1

我不知道這是不是你要找的。也許有一些示例數據可以改進我的查詢。有了這個你把所有產品的SKU在一個網站（對於單品與一個以上的產品）

SELECT 
    b.`website_id`, a.sku, 
    group_concat(DISTINCT a.`product_id`) as sku_products 
FROM `products` AS a 
    LEFT JOIN `website_products` AS b 
     ON (a.`product_id` = b.`product_id`) 
GROUP BY b.`website_id`, a.`sku` 
HAVING count(distinct a.`product_id`) > 1 
ORDER BY b.`website_id`