2

我有一个事件记录数据库，我需要找到每个客户的所有事件，并从每个客户的最后一条记录到第一个记录以一周的间隔对它们进行分组。

FirstEvent                  LastEvent               Client
==
2011-01-01 06:55:21.000 |2011-04-30 21:46:09.000    |Client1
2011-01-01 06:20:00.000 |2011-02-23 12:43:55.000    |Client2
2011-01-03 08:34:33.000 |2011-04-30 09:00:39.000    |Client3
2011-01-01 02:14:45.000 |2011-04-30 15:31:41.000    |Client4
2011-01-01 08:08:12.000 |2011-02-21 09:41:28.000    |Client5
2011-02-01 11:29:28.000 |2011-04-29 09:13:25.000    |Client6

现在我必须计算每个客户的记录并像这样对它们进行分组

Client     From                    To                        Records
==
Client1   |2011-04-30 21:46:09.000 |2011-04-23 21:46:09.000  |200
Client1   |2011-04-16 21:46:09.000 |2011-04-09 21:46:09.000  |400
                                 ...Until the the first date
Client1   |2011-01-08 06:55:21.000 |2011-01-01 06:55:21.000  |250
Client2   |2011-02-23 12:43:55.000 |2011-02-16 12:43:55.000  |50
                                 ...The same for each user

我希望有人可以帮助我找到一种方法来输出这个。

4

3 回答 3

2

您可以使用 DATEDIFF 函数按周分组。

SELECT e.[Client]
, [From] = MIN(e.EventDate)
, [To] = MAX(e.EventDate)
, [Records] = COUNT(*)
FROM Events AS e
GROUP BY e.[Client]
, DATEDIFF(week, '1900-01-01', e.EventDate)
于 2012-04-10T11:29:54.897 回答
1

好的，我认为这正是您想要的：

SELECT CONVERT(datetime, '2011-01-01 06:55:21.000', 120) AS event, 'client1' AS Client
INTO #EVENTS
UNION ALL SELECT '2011-01-08 06:55:20.000', 'client1'
UNION ALL SELECT '2011-04-30 21:46:09.000', 'client1'


;WITH E AS (
    SELECT
        Client,
        MIN(event) AS FirstEvent
    FROM #EVENTS
    GROUP BY Client
)
,B AS (
    SELECT
        E.Client,
        E.FirstEvent,
        COUNT(*) AS Records,
        DATEDIFF(DAY, 0, c.event - E.FirstEvent) / 7 AS [weeks]     
    FROM #EVENTS c
    JOIN E ON E.Client = c.Client
    GROUP BY E.Client, E.FirstEvent, DATEDIFF(DAY, 0, c.event - E.FirstEvent) / 7
)
SELECT
    Client,
    DATEADD(WEEK, weeks, FirstEvent) AS [From],
    DATEADD(WEEK, weeks + 1, FirstEvent) AS [To],
    Records
FROM B
ORDER BY Client, weeks;

DROP TABLE #EVENTS

但是，如果某一周没有记录，它将忽略该行，而不是返回包含 Records 值为 0 的行：

编辑：

如果您想知道为什么我使用DAY而不是WEEKfor my DATEDIFF，这是为了避免周日或周一是一周的第一天的问题。

于 2012-04-10T11:37:47.010 回答
0

如果开始和结束之间的周数小于 2048，这应该有效，如果不是，那么我建议使用数字表。

SELECT
client
,DATEADD(WK,(number * -1) -1,fromdate) as [from]
,DATEADD(WK,number * -1,fromdate) as [to]
,COUNT(client) as records
from #sample
LEFT OUTER JOIN (SELECT number FROM dbo.spt_values WHERE type = 'p') nums 
on nums.number <= DATEDIFF(WK,todate,fromdate)
GROUP BY client
,DATEADD(WK,(number * -1) -1,fromdate) 
,DATEADD(WK,number * -1,fromdate) 
ORDER BY 
client
,DATEADD(WK,(number * -1) -1,fromdate) DESC
于 2012-04-10T11:53:43.107 回答