Question

假设我有下表：

Table A: Event Log

ID        Step        WeekArrived        WeekCompleted
-------------------------------------------------------
1         A           1                  1
1         B           1                  3
2         B           3                  3

所以在第1周，案例1到了。对于这种情况，步骤A在第1周完成，但步骤B不是。步骤B在第3周完成。案例2也在第3周到达，步骤B在同一周完成（本案不需要步骤A）。

我想将此事件日志聚合成每周一步的概述，如下所示：

Table B: Weekly Overview

Week      Step        In                 Backlog               Out
------------------------------------------------------------------
1         A           1                  0                     1
1         B           1                  1                     0
2         A           0                  0                     0
2         B           0                  1                     0
3         A           0                  0                     0
3         B           1                  0                     2

对于每周X和步骤Y，此表显示：

In：在第X周开始第Y步的案例数
积压工作：在第X周结束时到达第Y步的案件数<= X，但尚未在第X周结束时完成。
Out：在第X周完成步骤Y的案例数

如何从表A到表B？

Answer 1

您需要一个周列表，以便评估该周是否有数据。

在sql server中，例如像How to generate a range of numbers between two numbers?

这样的东西

然后你加入你的步骤。如果您还有一个分开的表格，那么效果会更好。

SELECT weeks.week_id, steps.step, 
       CASE WHEN s_in.WeekArrived IS NULL THEN 0 ELSE 1 END as step_in,
       CASE WHEN s_completed.WeekCompleted IS NULL THEN 0 ELSE 1 END as step_out,
       CASE WHEN s_pending.WeekArrived IS NULL THEN 0 ELSE 1 END as step_pending
FROM weeks
CROSS JOIN (SELECT DISTINCT step
            FROM event_log) as steps

LEFT JOIN event_Log as s_in
  ON weeeks.week_id = e.WeekArrived
 AND steps.step = e.step

LEFT JOIN event_Log as s_completed
  ON weeeks.week_id = e.WeekCompleted
 AND steps.step = e.step

LEFT JOIN event_Log as s_pending
  ON weeeks.week_id > e.WeekArrived
 AND weeeks.week_id < e.WeekCompleted
 AND steps.step = e.step

注意：不知道back log是什么。

Answer 2

首先，您需要一种获取week_id列表的方法，我使用了Teradata的系统日历。然后是交叉加入加上一些条件聚合：

SELECT week_id, step,
   Sum(CASE WHEN week_id = WeekArrived THEN 1 ELSE 0 END) AS "in",
   Sum(CASE WHEN week_id >= WeekArrived AND week_id < WeekCompleted THEN 1 ELSE 0 END) as "backlog",
   Sum(CASE WHEN week_id = WeekCompleted THEN 1 ELSE 0 END) AS "out"
FROM
 ( -- get a lsit of week ids
   SELECT day_of_calendar AS week_id
   FROM sys_calendar.CALENDAR
   WHERE week_id
   -- calculate the range of week ids
   BETWEEN (SELECT Min(WeekArrived) FROM event_log)
       AND (SELECT Max(WeekCompleted) FROM event_log)
 ) AS weeks
CROSS JOIN
 (
   SELECT  *
   FROM event_log
 ) AS steps
GROUP BY week_id, step
ORDER BY week_id, step

将事件日志聚合到每周概述

2 个答案: