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这是数据库的一部分：

SessionID    SessionStartTime              SessionCloseTime
24       2012-10-16 01:00:06.000           2012-10-16 01:01:22.000
24       2012-10-16 01:00:08.000           2012-10-16 01:01:10.000
24       2012-10-16 01:00:16.000           2012-10-16 01:01:12.000
24       2012-10-16 01:00:30.000           2012-10-16 01:01:48.000
24       2012-10-16 01:00:41.000           2012-10-16 01:02:08.000
24       2012-10-16 01:00:48.000           2012-10-16 01:01:34.000
24       2012-10-16 01:00:56.000           2012-10-16 01:03:09.000
24       2012-10-16 01:01:02.000           2012-10-16 01:02:13.000
24       2012-10-16 01:01:05.000           2012-10-16 01:03:16.000
24       2012-10-16 01:01:09.000           2012-10-16 01:02:42.000
24       2012-10-16 01:01:15.000           2012-10-16 01:02:48.000
24       2012-10-16 01:01:18.000           2012-10-16 01:02:14.000
24       2012-10-16 01:01:18.000           2012-10-16 01:02:06.000
24       2012-10-16 01:01:42.000           2012-10-16 01:03:16.000
24       2012-10-16 01:01:45.000           2012-10-16 01:03:04.000

在这个数据库中，我想计算最大调用峰值。换句话说，最多同时发生多少呼叫。我在呼叫中心工作，我将使用这些记录生成报告。SessionID = 24 代表来电。任何建议、线索或计算方法都会对我有用。

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2 回答 2

1

通话开始时，通话次数会增加。通话结束时，通话次数会减少。所以...

;with cte as
(
    select SessionStartTime as changetime,1 as CC from yourtable
    union all
    select SessionCloseTime,-1 from yourtable
)
    select top 1 changetime,rt from
    (
    select * from cte
        cross apply 
        (select SUM(cc) as rt from cte c where c.changetime<=cte.changetime) rt         
    ) v
    order by rt desc
于 2012-10-24T07:58:49.980 回答
0

在这种情况下，听起来您需要一个数字表来加入会话存活的秒数。该表必须设置为您能够查询的最大时间长度（以秒为单位）。

使用这样的表，您可以编写如下查询：

CREATE TABLE Numbers 
( 
    Number INT IDENTITY(1,1) PRIMARY KEY CLUSTERED 
) 

WHILE COALESCE(SCOPE_IDENTITY(), 0) <= 1000000
BEGIN 
    INSERT #Numbers DEFAULT VALUES 
END

CREATE TABLE #Calls
(
    SessionID int,
    SessionStartTime datetime,
    SessionCloseTime datetime
)


INSERT INTO #Calls VALUES (24, '2012-10-16 01:00:06.000', '2012-10-16 01:01:22.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:00:08.000', '2012-10-16 01:01:10.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:00:16.000', '2012-10-16 01:01:12.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:00:30.000', '2012-10-16 01:01:48.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:00:41.000', '2012-10-16 01:02:08.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:00:48.000', '2012-10-16 01:01:34.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:00:56.000', '2012-10-16 01:03:09.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:02.000', '2012-10-16 01:02:13.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:05.000', '2012-10-16 01:03:16.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:09.000', '2012-10-16 01:02:42.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:15.000', '2012-10-16 01:02:48.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:18.000', '2012-10-16 01:02:14.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:18.000', '2012-10-16 01:02:06.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:42.000', '2012-10-16 01:03:16.000')
INSERT INTO #Calls VALUES (24, '2012-10-16 01:01:45.000', '2012-10-16 01:03:04.000')


SELECT TOP 1 DATEADD(SECOND, Number, SessionStartTime) CallTime, COUNT(C.SessionId) NoOfCalls FROM #Calls C
INNER JOIN #Numbers N ON N.Number <= DATEDIFF(SECOND, C.SessionStartTime, C.SessionCloseTime) --Join number of seconds between start and end time
GROUP BY DATEADD(SECOND, Number, SessionStartTime)
ORDER BY NoOfCalls DESC

此查询给出结果：

这些时间有 11 个电话：（当然是其中的前 1 个）

2012-10-16 01:01:47.000
2012-10-16 01:01:22.000
2012-10-16 01:01:21.000
2012-10-16 01:01:46.000
2012-10-16 01:01:48.000
2012-10-16 01:01:19.000
2012-10-16 01:01:20.000

于 2012-10-24T07:56:06.437 回答