Presto/AWS Athena - 选择记录的最新版本

Question

我有一个订单事件表，每个订单在填满时包含几个条目。有些订单被取消或退款。我正在尝试选择最新版本状态为"订单确认"的所有订单的最新版本，我以为我会使用以下 SQL，但 AWS Athena 抱怨无法解析列"latest_order_update.latest_update"。有什么线索吗？

WITH latest_order_update AS (
SELECT orderevent_order.unique_id, MAX(orderevent_order.event_time) AS latest_update
FROM orderevent_order
GROUP BY orderevent_order.unique_id)
SELECT orderevent_order.unique_id
FROM orderevent_order
WHERE orderevent_order.event_time = latest_order_update.latest_update AND orderevent_order.header_event_name = 'OrderConfirmed'
LIMIT 10;

Answer 1

你可以用ROW_NUMBER重写它：

WITH cte AS (
SELECT oo.unique_id,
,ROW_NUMBER() OVER(PARTITION BY unique_id ORDER BY event_time DESC) rn
FROM orderevent_order oo
)
SELECT * 
FROM cte
WHERE rn = 1;

或者在/subqueryFROM/JOIN中引用 cte：

WITH latest_order_update AS (
SELECT orderevent_order.unique_id, 
MAX(orderevent_order.event_time) AS latest_update
FROM orderevent_order
GROUP BY orderevent_order.unique_id)
SELECT orderevent_order.unique_id
FROM orderevent_order
WHERE orderevent_order.event_time IN (SELECT l.latest_update 
FROM latest_order_update l
WHERE orderevent_order.unique_id 
= l.unique_id)           
AND orderevent_order.header_event_name = 'OrderConfirmed'
LIMIT 10;

加入：

WITH latest_order_update AS (
SELECT orderevent_order.unique_id, 
MAX(orderevent_order.event_time) AS latest_update
FROM orderevent_order
GROUP BY orderevent_order.unique_id)
SELECT orderevent_order.unique_id
FROM orderevent_order
JOIN latest_order_update
ON orderevent_order.event_time = latest_order_update.latest_update
AND orderevent_order.unique_id = latest_order_update.unique_id
WHERE orderevent_order.header_event_name = 'OrderConfirmed'
LIMIT 10;