按ID分組具有最大值（日期字段）

Question

要構建報表，我必須選擇一些關於所有客戶的最後交易狀態的信息。到現在爲止，這是我的了：

SELECT c.firstname, c.lastname, d.product_name, o.payment, s.name, h.date_add 
FROM ps_orders o 
INNER JOIN ps_order_detail d ON d.id_order = o.id_order 
INNER JOIN ps_customer c ON c.id_customer = o.id_customer 
INNER JOIN ps_order_history h ON o.id_order = h.id_order 
INNER JOIN ps_order_state_lang s ON s.id_order_state = h.id_order_state 
WHERE s.id_lang =6 
GROUP BY c.id_customer 
HAVING MAX(h.date_add) 

對每一個客戶，該查詢選擇的第一個日期（場h.date_add）當我需要的最後一個。 MySQL似乎無視HAVING。

我試圖做出一個子選擇，但它不起作用。

謝謝任何​​答案。

Answer 1

在這裏，您需要獲取最新date_add的子查詢，對於表ps_order_history上的每個id_order。然後將子查詢的結果加回到原始表ps_order_history上，前提是它在兩列上進行匹配：date_add和id_order。

SELECT c.firstname, 
     c.lastname, 
     d.product_name, 
     o.payment, 
     s.name, 
     h.date_add 
FROM ps_orders o 
     INNER JOIN ps_order_detail d ON d.id_order = o.id_order 
     INNER JOIN ps_customer c ON c.id_customer = o.id_customer 
     INNER JOIN ps_order_history h ON o.id_order = h.id_order 
     INNER JOIN 
     (
      SELECT id_order, MAX(date_add) max_date 
      FROM ps_order_history 
      GROUP BY id_order 
     ) x ON h.id_order = x.id_order AND 
       h.date_add = x.max_date 
     INNER JOIN ps_order_state_lang s ON s.id_order_state = h.id_order_state 
WHERE s.id_lang =6 
GROUP BY c.id_customer 

Answer 2

要獲得的最後一天，你需要加入它：

SELECT c.firstname, c.lastname, d.product_name, o.payment, s.name, h.date_add 
FROM ps_orders o 
INNER JOIN ps_order_detail d ON d.id_order = o.id_order 
INNER JOIN ps_customer c ON c.id_customer = o.id_customer 
INNER JOIN ps_order_history h ON o.id_order = h.id_order 
INNER JOIN ps_order_state_lang s ON s.id_order_state = h.id_order_state 
inner join (select o.id_customer, max(oh.date_add) as maxdate from ps_order_history h join ps_order o on h.id_order = o.id_order group by o.id_customer) omax on omax.id_customer = o.id_customer and o.date_add = omax.maxdate 
WHERE s.id_lang =6 
GROUP BY c.id_customer 

你having子句計算最大日期，然後成功時，它不等於0（這將是最時間）。