MYSQL 窗口函数

Question

订单在最终交付给客户之前有多个order_status。有时客户会从不同来源下多个订单。我们接受一份订单，但拒绝另一份订单。我想知道重复订单被取消后，已接受订单的最新订单状态是什么。

LEFT JOIN(
            SELECT order_id AS order_id,order_status,max(addtime(`timestamp`,'05:30:00')) AS timestamp
            FROM pe2.order_history
            GROUP BY 1,2
) oh ON oh.order_id = ord.order_id AND oh.timestamp <= c.time. 
c.time. is duplicate order cancellation time.

Answer 1

我们获取所需客户的订单，然后我们获取同一订单的最新状态，即取消重复订单之前的状态:

SELECT order.*,
(SELECT order_status FROM order_history AS oh 
WHERE order_id = order.id AND timestamp <= cancel_time
ORDER BY timestamp DESC LIMIT 1) AS last_status
FROM order
WHERE order.ID = accepted_order