Question

我从3个不同的表格中获取了数据，如下所示。在这里我获取数据，但在与where Convert(Varchar(10),DWA.Date,111)<convert(Varchar(10),DFD.Date_of_Filling,111)比较后只获得最小数据。

我需要表MD中提供的完整数据，但由于条件的原因而无法获取。请帮助。

不仅我需要AVG(cast(DWA.Airtel as int)) as Avg_DG_Run平均可用的最后3个日期。

请帮助

SELECT md.IndusID, 
       md.Site_Name, 
       md.ANCHOR_OPCO, 
       md.DISTRICT, 
       md.TECH_NAME, 
       md.TECH_No, 
       md.OME_Technical_Manager_Name, 
       md.DIESEL_FILLER, 
       md.DIESEL_FILLER_MOB, 
       md.EB_DG, 
       md.Min_Stock_Req, 
       md.Actual_CPH, 
       Sum(Cast(dfd.Qty_Filled AS INT))                    AS This_Month_Filling 
       , 
       Max(CONVERT(VARCHAR(10), DFD.Date_of_Filling, 111)) AS 
       Last_Filling_Date, 
       Avg(Cast(DWA.Airtel AS INT))                        AS Avg_DG_Run, 
       Sum(Cast(DWA.DG_RUN AS INT))                        AS DGRun 
FROM   MasterData MD 
       LEFT JOIN DieselFillingData DFD 
              ON md.IndusID = dfd.Site_ID 
       LEFT JOIN DayWiseAlarm DWA 
              ON md.IndusID = dwa.Indus_ID 
WHERE  CONVERT(VARCHAR(10), DWA.Date, 111) < 
       CONVERT(VARCHAR(10), DFD.Date_of_Filling, 111) 
GROUP  BY md.IndusID, md.Site_Name, md.ANCHOR_OPCO, md.DISTRICT, md.TECH_NAME, 
          md.TECH_No, md.OME_Technical_Manager_Name, md.DIESEL_FILLER, 
          md.DIESEL_FILLER_MOB, md.EB_DG, md.Min_Stock_Req, md.Actual_CPH 
ORDER  BY md.OME_Technical_Manager_Name, 
          md.TECH_NAME

Answer 1

我明白了。 where条件将外连接转换为内连接。将条件移动到on子句：

FROM MasterData MD LEFT JOIN
     DieselFillingData DFD 
     ON md.IndusID = dfd.Site_ID LEFT JOIN
     DayWiseAlarm DWA 
     ON md.IndusID = dwa.Indus_ID AND
        CONVERT(VARCHAR(10), DWA.Date, 111) < CONVERT(VARCHAR(10), DFD.Date_of_Filling, 111)

将日期转换为字符串进行比较似乎是一个坏主意。这应该做你想要的：

FROM MasterData MD LEFT JOIN
     DieselFillingData DFD 
     ON md.IndusID = dfd.Site_ID LEFT JOIN
     DayWiseAlarm DWA 
     ON md.IndusID = dwa.Indus_ID AND
        DWA.Date < DFD.Date_of_Filling

需要过去3个日期的平均数据

1 个答案: