TSQL使用具有不同联接的同一表进行多次计数

我有一个奇怪的情况，不太确定如何处理它

我有两张单独的桌子：

表A是提交的材料

id
submitterQID
nomineeQID
story

表B为雇员人数

QID
Name
Department

我正试图获得按部门分组的提交书总数以及提名总数

这就是我的存储过程的样子：

BEGIN
                SELECT   TOP 50 count(A.[nomineeQID]) AS totalNominations,
                                count(A.[subQID]) AS totalSubmissions,
                                B.[DepartmentDesc] AS department
                FROM     empowermentSubmissions AS A
                JOIN empTable AS B
                ON B.[qid] = A.[nomineeQID]
                WHERE A.[statusID] = 3
                AND A.[locationID] = @locale
                GROUP BY B.[Department]
                ORDER BY totalNominations DESC
                FOR      XML PATH ('data'), TYPE, ELEMENTS, ROOT ('root');
            END

这个问题是联接仅由

指定的QID

联接，而不是

子QID

联接

我期待的最终结果是：

部门客户服务部有25份意见书和90份提名

按两个计数之和排序

我试图在

subQID

上再次加入

JOIN

，但被告知不能在同一个表上加入两次

---

有没有更简单的方法来实现这一点

在这种情况下，您需要彼此独立地收集计数。使用两个左联接将导致当两个联接都满足联接条件时，在第一个左联接中对某些行计数两次。您的场景可以使用相关子查询或外部应用程序来解决，该应用程序收集不同条件下的计数。我没有在这里提供一个

COUNT（CASE…

选项，因为数据中没有非此即彼的场景，您有两个外键指向employees表。因此，设置示例数据：

declare @empowermentSubmissions table (submissionID int primary key identity(1,1), submissionDate datetime, nomineeQID INT, submitterQID INT, statusID INT, locationID INT)
declare @empTable table (QID int primary key identity(1,1), AreaDesc varchar(10), DepartmentDesc varchar(20))
declare @locale INT = 0
declare @n int = 1

while @n < 50
begin
    insert into @empTable (AreaDesc, DepartmentDesc) values ('Area ' + cast((@n % 2)+1 as varchar(1)), 'Department ' + cast((@n % 4)+1 as varchar(1)))
    set @n = @n + 1
end
set @n = 1
while @n < 500
begin
    insert into @empowermentSubmissions (submissionDate, nomineeQID, submitterQID, StatusID, locationID) values (dateadd(dd,-(cast(rand()*600 as int)),getdate()), (select top 1 QID from @empTable order by newid()), (select top 1 QID from @empTable order by newid()), 3 + (@n % 2) - (@n % 3), (@n % 2) )
    set @n = @n + 1
end

---

我的一个大问题是在这方面的表现。它似乎在浏览整个employeeTable，然后当它在submissions表中找到某个内容时，它就完成了自己的工作。empTable包含超过10k的记录，所以我想知道这是否会成为一个问题。当我在我的表格上运行代码时，它试图将数据返回给每个员工。啊，我错过了部门。无论如何，它都必须重复员工记录，按部门分组，并获得提名/提交数量，但我在这方面做得很糟糕。请参阅我的编辑。至于性能，如果在索引中配对empowermentSubmissions.NamedQid和empowermentSubmissions.locationID，并且在索引中配对empowermentSubmissions.submitterQID和empowermentSubmissions.locationID，这应该会非常快。10K记录不应该成为问题。

SELECT TOP 50 E.DepartmentDesc, SUM(N.Nominations) Nominations, SUM(S.TotalSubmissions) TotalSubmissions
FROM @empTable E
    OUTER APPLY (
        SELECT COUNT(submissionID) Nominations
        FROM @empowermentSubmissions A
        WHERE A.statusID = 3
            AND A.nomineeQID = E.QID
            AND A.locationID = @locale
    ) N
    OUTER APPLY (
        SELECT COUNT(submissionID) TotalSubmissions
        FROM @empowermentSubmissions A
        WHERE A.statusID = 3
            AND A.submitterQID = E.QID
            AND A.locationID = @locale
    ) S
GROUP BY E.DepartmentDesc
ORDER BY SUM(Nominations) + SUM(TotalSubmissions) DESC