如何按不同的员工正确分组数据

Question

我有两张数据表，一张是交易表，将每位员工与 2020 财年的软件使用情况联系起来，另一张是员工表。它们有一个称为 trackingid 的主键关系。因此，对于一名员工，他们可以进行许多交易。我们还会计算软件的使用小时数，并将其加总为使用天数。

我的目标是生成一份报告，其中显示不同用户、其他列以及正确分组的计算使用天数。每次我试图让选择起作用时，我都会得到 1 行每个软件实例的使用时间。

由于我不太擅长 SQL，我在 GROUP BY 和 AGGREGATE 函数上苦苦挣扎，我需要正确生成此输出。

select DISTINCT w.[TrackingId], w.[FirstName], w.[LastName], w.[Email], w.UserName, 
w.[OfficeAddress1], w.[OfficeCity],w.[OfficeCountry], w.[OfficePostCode], w.[SupervisorName],w.[Department], w.[DepartmentName],w.[Organization], t.ProductName, t.FiscalPeriod, t.UsageHours
from 
 dbo.Employee_Users w INNER JOIN
 dbo.SoftwareTransactions t ON w.TrackingID = t.TrackingId

示例数据如下所示：

FirstName,LastName,Email,UserName,OfficeAddress1,OfficeCity,OfficeCountry,OfficePostCode,SupervisorName,Department,DepartmentName,Organization,ProductName,FiscalPeriod,UsageHours
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q1-10,0.107
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q1-12,0.316
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q1-12,1.627
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-01,0.027
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-01,1.21
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-01,4.548
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-02,0.02
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-02,0.911
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-03,7.022
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-03,104.896
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q2-03,148.505
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q3-04,719.469
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q3-06,2260.458
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q4-07,616.381
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q4-09,1846.506
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,ARC/INFO,FY2020-Q4-09,2489.788
Employee1,Employee1LN,Employee1.Employee1LN@Company.com,Employee1LNA,Siemensstr 10,Neu-Isenburg,Germany,63263,"Supervisor1",A224,522.DEU EMIA MGMT Ops IT,52.Company GMBH.EUDEU1.A224,Viewer,FY2020-Q1-10,1.792

Answer 1

在实践中 SELECT DISTINCT 只是执行特定类型的 GROUP BY 的一种更简单的方法 - 您对每个字段进行 GROUP BY。

例如，

SELECT DISTINCT a, b, c
FROM mytable;

等价于

SELECT a, b, c
FROM mytable
GROUP BY a, b, c

但是，如果您不想要按所有字段进行分组，则需要使用 GROUP BY 子句。

我做这些的方法是从我们期望在一行上的东西开始（和 GROUP BY 这些）。在您的情况下，我猜这将是每个会计年度的用户产品。

因此，我将从我们想要对其进行 GROUP BY 的所有相关行开始（注意 - 这只是最后一个字段）

select 
    w.[TrackingId], 
    w.[FirstName], 
    w.[LastName], 
    w.[Email], 
    w.UserName, 
    w.[OfficeAddress1], 
    w.[OfficeCity],
    w.[OfficeCountry], 
    w.[OfficePostCode], 
    w.[SupervisorName],
    w.[Department], 
    w.[DepartmentName],
    w.[Organization], 
    t.ProductName, 
    t.FiscalPeriod
from 
    dbo.Employee_Users w 
    INNER JOIN dbo.SoftwareTransactions t ON w.TrackingID = t.TrackingId
group by
    w.[TrackingId], 
    w.[FirstName], 
    w.[LastName], 
    w.[Email], 
    w.UserName, 
    w.[OfficeAddress1], 
    w.[OfficeCity],
    w.[OfficeCountry], 
    w.[OfficePostCode], 
    w.[SupervisorName],
    w.[Department], 
    w.[DepartmentName],
    w.[Organization], 
    t.ProductName, 
    t.FiscalPeriod;

上面应该给你正确的行数。

接着，添加“聚合”值 - 这些值包含多行并汇总为一个。

在你的情况下，我猜你想要总小时数（得到总小时数）。

所以最终的答案是

select 
    w.[TrackingId], 
    w.[FirstName], 
    w.[LastName], 
    w.[Email], 
    w.UserName, 
    w.[OfficeAddress1], 
    w.[OfficeCity],
    w.[OfficeCountry], 
    w.[OfficePostCode], 
    w.[SupervisorName],
    w.[Department], 
    w.[DepartmentName],
    w.[Organization], 
    t.ProductName, 
    t.FiscalPeriod,
    SUM(t.UsageHours) as TotalUsageHours    /* this is the only row added */
from 
    dbo.Employee_Users w 
    INNER JOIN dbo.SoftwareTransactions t ON w.TrackingID = t.TrackingId
group by
    w.[TrackingId], 
    w.[FirstName], 
    w.[LastName], 
    w.[Email], 
    w.UserName, 
    w.[OfficeAddress1], 
    w.[OfficeCity],
    w.[OfficeCountry], 
    w.[OfficePostCode], 
    w.[SupervisorName],
    w.[Department], 
    w.[DepartmentName],
    w.[Organization], 
    t.ProductName, 
    t.FiscalPeriod;