按ID分组具有最大值（日期字段）

Question

要构建报表，我必须选择一些关于所有客户的最后交易状态的信息。到现在为止，这是我的了：

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) 

对每一个客户，该查询选择的第一个日期（场h.date_add）当我需要的最后一个。 MySQL似乎无视HAVING。

我试图做出一个子选择，但它不起作用。

谢谢任何​​答案。

Answer 1

在这里，您需要获取最新date_add的子查询，对于表ps_order_history上的每个id_order。然后将子查询的结果加回到原始表ps_order_history上，前提是它在两列上进行匹配：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

要获得的最后一天，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子句计算最大日期，然后成功时，它不等于0（这将是最时间）。