在 SQL 中使用带等级和子查询的 where 语句

Question

所以我有一张类似这样的表：

DELIVERY_AREA_ID	DELIVERY_RADIUS_METERS 交付	EVENT_STARTED_TIMESTAMP
234sfd	4000	2020-01-01 12:19:29.719
234sfd	6500	2020-01-01 12:31:40.325
234sfd	3500	2020-01-01 12:53:10.538
234sfd	6500	2020-01-01 13:11:36.094
234sfd	3500	2020-01-01 13:32:26.754
234sfd	6500	2020-01-01 13:59:11.104
234sfd	6500	2020-01-02 07:44:16.792
234sfd	3500	2020-01-02 08:07:36.284
234sfd	6500	2020-01-02 08:54:08.014
234sfd	3500	2020-01-02 09:53:05.853
234sfd	6500	2020-01-02 10:04:39.443
234sfd	10000	2020-07-01 08:29:20.194
234sfd	3500	2020-07-03 07:50:41.782
234sfd	10000	2020-07-03 08:33:14.695
234sfd	3500	2020-07-05 07:47:05.539
234sfd	10000	2020-07-05 07:53:13.930
234sfd	3500	2020-07-05 09:18:57.688
234sfd	10000	2020-07-05 09:51:07.547
234sfd	3500	2020-07-19 18:02:14.099

数据实际上更加多样化，但是是的，它遵循这种格式。

我试图在一个查询中，在雪花数据库中，按持续时间获得排名最高的半径。 我目前有这个：

SELECT DELIVERY_AREA_ID,
       MAX(DELIVERY_RADIUS_METERS) AS default_delivery_radius,
       MONTH_YEAR,
       DELIVERY_RADIUS_METERS,
       SUM(DURATION_SECONDS) AS total_duration,
       MAX(EVENT_STARTED_TIMESTAMP) AS MAX_TIMESTAMP,
       RANK() OVER (PARTITION BY DELIVERY_AREA_ID, MONTH_YEAR
                    ORDER BY SUM(DURATION_SECONDS) DESC) AS RADIUS_RANK
FROM (
    -- Add the MONTH_YEAR column to the delivery_radius_log table
    SELECT DELIVERY_AREA_ID,
           DELIVERY_RADIUS_METERS,
           EVENT_STARTED_TIMESTAMP,
           CONCAT(MONTH(EVENT_STARTED_TIMESTAMP), '/',
                  YEAR(EVENT_STARTED_TIMESTAMP)) AS MONTH_YEAR,
           DATEADD(second, DATEDIFF(second, EVENT_STARTED_TIMESTAMP, LEAD(EVENT_STARTED_TIMESTAMP) OVER (PARTITION BY DELIVERY_AREA_ID ORDER BY EVENT_STARTED_TIMESTAMP)), EVENT_STARTED_TIMESTAMP) AS end_timestamp,
           DATEDIFF(second, EVENT_STARTED_TIMESTAMP, LEAD(EVENT_STARTED_TIMESTAMP) OVER (PARTITION BY DELIVERY_AREA_ID ORDER BY EVENT_STARTED_TIMESTAMP)) AS duration_seconds
    FROM delivery_radius_log
) t  -- added alias here
GROUP BY DELIVERY_AREA_ID, MONTH_YEAR, DELIVERY_RADIUS_METERS

我想获得每个 month_year 的第一名但是当我使用

where RADIUS_RANK = 1

我收到一个错误：语法错误：意外的“哪里”。 （第 21 行）

我不确定如何解决这个问题

我试过这个链接似乎有同样的问题，但解决方案已经是我正在尝试的。

Answer 1

不查询查询的输出就不可能解决这种情况，换句话说，使用该查询的输出作为另一个顶级查询的输入。

• 您不能在 WHERE 子句中使用在投影级别生成的字段
• 不能在 WHERE 子句中使用解析函数
• 不能在 HAVING 子句中使用分析函数

因此唯一的解决方案是查询该查询的输出并仅检索 MIN 排名。

Answer 2

要在同一查询级别过滤窗口函数，您需要使用QUALIFY子句：

SELECT DELIVERY_AREA_ID,
       MAX(DELIVERY_RADIUS_METERS) AS default_delivery_radius,
       MONTH_YEAR,
       DELIVERY_RADIUS_METERS,
       SUM(DURATION_SECONDS) AS total_duration,
       MAX(EVENT_STARTED_TIMESTAMP) AS MAX_TIMESTAMP,
       RANK() OVER (PARTITION BY DELIVERY_AREA_ID, MONTH_YEAR
                    ORDER BY SUM(DURATION_SECONDS) DESC) AS RADIUS_RANK
FROM (
    -- Add the MONTH_YEAR column to the delivery_radius_log table
    SELECT DELIVERY_AREA_ID,
           DELIVERY_RADIUS_METERS,
           EVENT_STARTED_TIMESTAMP,
           CONCAT(MONTH(EVENT_STARTED_TIMESTAMP), '/',
                  YEAR(EVENT_STARTED_TIMESTAMP)) AS MONTH_YEAR,
           DATEADD(second, DATEDIFF(second, EVENT_STARTED_TIMESTAMP, LEAD(EVENT_STARTED_TIMESTAMP) OVER (PARTITION BY DELIVERY_AREA_ID ORDER BY EVENT_STARTED_TIMESTAMP)), EVENT_STARTED_TIMESTAMP) AS end_timestamp,
           DATEDIFF(second, EVENT_STARTED_TIMESTAMP, LEAD(EVENT_STARTED_TIMESTAMP) OVER (PARTITION BY DELIVERY_AREA_ID ORDER BY EVENT_STARTED_TIMESTAMP)) AS duration_seconds
    FROM delivery_radius_log
) t  -- added alias here
GROUP BY DELIVERY_AREA_ID, MONTH_YEAR, DELIVERY_RADIUS_METERS
QUALIFY RADIUS_RANK = 1;

如果不需要排名列，则可以移动整个表达式：

SELECT DELIVERY_AREA_ID,
       MAX(DELIVERY_RADIUS_METERS) AS default_delivery_radius,
       MONTH_YEAR,
       DELIVERY_RADIUS_METERS,
       SUM(DURATION_SECONDS) AS total_duration,
       MAX(EVENT_STARTED_TIMESTAMP) AS MAX_TIMESTAMP
FROM (
    -- Add the MONTH_YEAR column to the delivery_radius_log table
    SELECT DELIVERY_AREA_ID,
           DELIVERY_RADIUS_METERS,
           EVENT_STARTED_TIMESTAMP,
           CONCAT(MONTH(EVENT_STARTED_TIMESTAMP), '/',
                  YEAR(EVENT_STARTED_TIMESTAMP)) AS MONTH_YEAR,
           DATEADD(second, DATEDIFF(second, EVENT_STARTED_TIMESTAMP, LEAD(EVENT_STARTED_TIMESTAMP) OVER (PARTITION BY DELIVERY_AREA_ID ORDER BY EVENT_STARTED_TIMESTAMP)), EVENT_STARTED_TIMESTAMP) AS end_timestamp,
           DATEDIFF(second, EVENT_STARTED_TIMESTAMP, LEAD(EVENT_STARTED_TIMESTAMP) OVER (PARTITION BY DELIVERY_AREA_ID ORDER BY EVENT_STARTED_TIMESTAMP)) AS duration_seconds
    FROM delivery_radius_log
) t  -- added alias here
GROUP BY DELIVERY_AREA_ID, MONTH_YEAR, DELIVERY_RADIUS_METERS
QUALIFY RANK() OVER (PARTITION BY DELIVERY_AREA_ID, MONTH_YEAR
                    ORDER BY SUM(DURATION_SECONDS) DESC) = 1;