Question

我正在尝试为电话系统创建利用率图表。我有表格格式的数据集

ID *
StartDate
EndDate
From
To

我想要做的就是让SQL每隔5分钟输出一个情节点列表，所以基本上

一天中每5分钟一次的活动呼叫计数（在StartDate和EndDate之间）。

结果好像是

Date Time             Count  
2000-01-01 00:00:00   10
2000-01-01 00:05:00   2
2000-01-01 00:10:00   7

有人可以建议一种生成所述数据的方法吗？我在这里不知所措！我一直在思考的东西都涉及创建一个大循环并且每5秒运行一次查询，这看起来非常低效。

我最初想的方法是： -

storedProc GetSamples(SampleStartDate, SampleEndDate)

    Create memory table for result data

    for every 5mins as sample between SampleStartDate and SampleEndDate
        SELECT @SampleCount = COUNT(1) FROM Samples where 5mins BETWEEN StartDate AND EndDate
        UPDATE memoryTable SET count=@SampleCount WHERE time = 5mins
    end
end

Answer 1

如果你有一个最近版本的SQL Server（2008+），你应该可以通过加入你的电话记录的CTE来做到这一点，就像这样（CTE base found here）：< / p>

DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate = '2000-01-01 00:00:00.000'
SET @EndDate = '2000-01-02 00:00:00.000'

;WITH DateSequence( [PlotPointDate] ) AS 
(
    SELECT @StartDate AS [PlotPointDate] 

    UNION ALL 

    SELECT DATEADD(MINUTE, 5, [PlotPointDate] )
    FROM DateSequence
    WHERE [PlotPointDate]  < @EndDate
)

--select result
SELECT 
    PlotPointDate, COUNT(YourTable.ID) AS TotalActiveCalls
FROM 
    DateSequence 
     LEFT JOIN 
    YourTable ON 
        YourTable.StartDate <= DateSequence.PlotPointDate AND
        (YourTable.EndDate >= DateSequence.PlotPointDate  OR YourTable.EndDate IS NULL)
GROUP BY PlotPointDate
OPTION (MaxRecursion 10000)

从日期范围有效地获取绘图数据

1 个答案: