Question

我正在处理Tableau Dashboard的Select查询，而select查询的条件是，如果查询为帐号提取多行，则需要将ProjectStartJobs和LocationEmployees值更改为Null。

SELECT 
    FA.AccountNumber AS AccountNumber
    ,YEAR(New_LandedDate) AS [Year]
    ,FO.New_LandedDate AS LandedDate
    ,FO.CustomerIDName AS Company
    ,FO.New_ProjectStartJobs AS ProjectStartJobs
    ,FA.New_LocationEmployees AS LocationEmployees
    ,FO.New_AnnouncedJobs AS AnnouncedJobs
    ,ISNULL(FA.New_LocationEmployees,0) - ISNULL(FO.new_projectstartjobs,0) AS [Job Creation]
    ,FC.Ecd_ecdregionname AS ECDRegion
    ,FC.Ecd_grandregionname AS GrandDivision
    ,FO.New_TaxTierName AS TaxTier
FROM FilteredOpportunity AS FO
    LEFT JOIN FilteredAccount AS FA
        ON FO.CustomerID = FA.AccountID
    LEFT JOIN FilteredNew_County AS FC
        ON FO.New_CountyID = FC.New_CountyID
WHERE (New_LandedDate >= '2011-01-01'
    AND New_LandedDate <= ( SELECT TOP 1 DATEADD(DD,-1,DATEADD(QQ,DATEDIFF(QQ,0,New_LandedDate),0)) FROM FilteredOpportunity ORDER BY New_LandedDate DESC))
    AND (New_AnnouncedJobs >= '50' OR New_ProjectactionCode = '100000000')
    AND new_projectactioncode <> '100000006'
ORDER BY  FA.Accountnumber , [LandedDate] DESC

Answer 1

您可以使用窗口函数检查每个帐户的行数，然后返回多于1的null，例如

,CASE WHEN COUNT(*) OVER(PARTITION BY FA.AccountNumber) > 1 THEN NULL 
    ELSE FO.New_ProjectStartJobs 
END AS ProjectStartJobs
,CASE WHEN COUNT(*) OVER(PARTITION BY FA.AccountNumber) > 1 THEN NULL 
    ELSE FO.New_LocationEmployees 
END AS LocationEmployees

修改

如果每个帐户的第一条记录都显示该值，那么您可以使用ROW_NUMBER() OVER()而不是COUNT(*) OVER()：

,CASE WHEN ROW_NUMBER() OVER(PARTITION BY FA.AccountNumber ORDER BY [LandedDate] DESC) > 1 THEN NULL ELSE FO.New_ProjectStartJobs END AS ProjectStartJobs ,CASE WHEN ROW_NUMBER() OVER(PARTITION BY FA.AccountNumber ORDER BY [LandedDate] DESC) > 1 THEN NULL ELSE FO.New_LocationEmployees END AS LocationEmployees

如果在“选择查询”中多次重复行，如何获取列值Null

1 个答案: