Question

我正在尝试根据报告类型计算关闭故障单所需的平均天数。

我想出了如何使用以下查询对任何一种类型的报告执行此操作：

SELECT

CONVERT(DATE,SubmitDate) as 'Date'
,SUM(DATEDIFF(DAY, SubmitDate, DateClosed)) / COUNT(*) as 'Report1Avg'

FROM Table1

    WHERE Status = 'Closed'
        AND ReportType = '1'

GROUP BY CONVERT(DATE,SubmitDate)

但是，我希望获得所有不同类型报告的平均值。我试图将结果集看起来如下所示：

Date Submitted  Report1Avg  Report2Avg  Report3Avg  Report4Avg
9/1/2015             5          10          11          NULL
9/2/2015           NULL         22           3           5
9/3/2015            1            3          NULL        NULL

这是表格：

ticket  SubmitDate  ReportType  Status  DateClosed
  1      3/7/2014       NULL    Closed  8/18/2014
  2     3/17/2014       1       Closed  3/19/2014
  3     3/17/2014       3       Closed   4/1/2014
  4     3/18/2014       3       Closed   4/1/2014
  5     3/18/2014       3       Closed   4/1/2014
  6     3/19/2014       4       Closed  3/19/2014
  7     3/25/2014       4       Closed  3/25/2014
  8     3/25/2014       2       Closed  3/31/2014
  9     3/25/2014       NULL    Closed  3/31/2014
 10     3/25/2014       1       Closed  3/31/2014

我尝试使用UNION但没有用。创建VIEW也不起作用。

我发现了一些类似的帖子，但它们并不涉及平均值。

感谢您的任何建议。

Answer 1

您需要做的就是修复group by条款：

SELECT
   CONVERT(DATE,SubmitDate) as 'Date',
   AVG(DATEDIFF(DAY, SubmitDate, DateClosed)) AS 'Report1Avg',
   ReportType
FROM Table1
   WHERE Status = 'Closed'
GROUP BY CONVERT(DATE,SubmitDate), ReportType

如果您希望根据示例格式化结果，请使用PIVOT语句。

Answer 2

这样的东西？

SELECT submitdate
    ,reporttype
    ,AVG(DATEDIFF(DAY, SubmitDate, DateClosed)) NUMBER_OF_DAYS
INTO #temp
FROM table1
WHERE Status = 'Closed'
GROUP BY SubmitDate,reporttype 

SELECT submitdate
    , CASE WHEN reporttype = 1 THEN (SELECT t2.NUMBER_OF_DAYS FROM #temp t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report1Avg
    , CASE WHEN reporttype = 2 THEN (SELECT t2.NUMBER_OF_DAYS FROM #temp t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report2Avg
    , CASE WHEN reporttype = 3 THEN (SELECT t2.NUMBER_OF_DAYS FROM #temp t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report3Avg
    , CASE WHEN reporttype = 4 THEN (SELECT t2.NUMBER_OF_DAYS FROM #temp t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report4Avg
FROM #temp t1

DROP TABLE #temp

或者有一个观点：

CREATE VIEW AVG_REPORT AS 
SELECT submitdate
    ,reporttype
    ,AVG(DATEDIFF(DAY, SubmitDate, DateClosed)) NUMBER_OF_DAYS
FROM table1
WHERE Status = 'Closed'
GROUP BY SubmitDate,reporttype

然后：

SELECT submitdate
    , CASE WHEN reporttype = 1 THEN (SELECT t2.NUMBER_OF_DAYS FROM AVG_REPORT t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report1Avg
    , CASE WHEN reporttype = 2 THEN (SELECT t2.NUMBER_OF_DAYS FROM AVG_REPORT t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report2Avg
    , CASE WHEN reporttype = 3 THEN (SELECT t2.NUMBER_OF_DAYS FROM AVG_REPORT t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report3Avg
    , CASE WHEN reporttype = 4 THEN (SELECT t2.NUMBER_OF_DAYS FROM AVG_REPORT t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report4Avg
FROM AVG_REPORT t1

也可以像这样使用公用表表达式（CTE）：

WITH
BASE AS ( 
SELECT submitdate
    ,reporttype
    ,AVG(DATEDIFF(DAY, SubmitDate, DateClosed)) NUMBER_OF_DAYS
FROM table1
WHERE Status = 'Closed'
GROUP BY SubmitDate,reporttype
)

SELECT submitdate
    , CASE WHEN reporttype = 1 THEN (SELECT t2.NUMBER_OF_DAYS FROM BASE t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report1Avg
    , CASE WHEN reporttype = 2 THEN (SELECT t2.NUMBER_OF_DAYS FROM BASE t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report2Avg
    , CASE WHEN reporttype = 3 THEN (SELECT t2.NUMBER_OF_DAYS FROM BASE t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report3Avg
    , CASE WHEN reporttype = 4 THEN (SELECT t2.NUMBER_OF_DAYS FROM BASE t2 WHERE t1.submitdate = t2.submitdate AND t1.reporttype = t2.reporttype) END Report4Avg
FROM BASE t1

如何基于多个WHERE子句组合多个平均计算？

2 个答案: