SQL 外部联接视图

Question

首先很抱歉，这个问题没有描述我的问题，我不知道如何将其作为问题来讲述。

我想统计每个分支机构有多少女性和男性有职位主管。

所以这是 SQL:

    CREATE VIEW Women (BranchID,AnzahlF,position ) AS
SELECT       Branch.BranchID, COUNT(*) As AnzahlF,Staff.position
FROM         Staff full outer JOIN
                      Branch ON Branch.BranchID = Staff.BranchFK
WHERE gender LIKE 'F' AND position LIKE 'Supervisor'
GROUP BY Branch.BranchID,Staff.position

CREATE VIEW Men (BranchID,AnzahlM,position ) AS
SELECT       Branch.BranchID,COUNT(*) As AnzahlM ,Staff.position
FROM         Staff Full outer JOIN
                      Branch ON Branch.BranchID = Staff.BranchFK
WHERE gender LIKE 'M' AND position LIKE 'Supervisor'
GROUP BY Branch.BranchID,Staff.position


    Select ISNULL(Women.BranchID, Men.BranchID) AS BranchID,
    Case When (Women.AnzahlF is Null) THEN  0 
ELSE Women.AnzahlF  END As ANzahlFSuperv,
    Case When (Men.AnzahlM is Null) THEN  0 
ELSE Men.AnzahlM  END As ANzahlMSuperv
    from Women  Full outer join Men  On Women.BranchID = Men.BranchID
    Group by Women.BranchID, Men.BranchID,Women.ANzahlF,Men.AnzahlM Order by BranchID

这是输出： BranchID、ANzahlFSuperv、ANzahlMSuperv
B001,2,0
B003,1,1
B004,1,1
B005,1,0
B006,1,0
B007,0,2
B008,1,1
B009,0,1
B010,0,1
B011,1,0
B012,0,1
B013,1,0
B014,1,0
=> 缺少 B002，0,0

但我没有得到 ID 为 'B002' 的分支，它有 ANzahlFSuperv = 0 和 ANzahlMSuperv = 0。所以它没有主管。那么如何得到这个结果呢？

解决方案一定在视图中，那么如何获取这个BranchID。

我什么都试过了，但毫无价值。

希望大家帮帮我！

谢谢！

Answer 1

为什么要为此使用视图？只是一个 left join 和 group by:

SELECT b.BranchID, COUNT(*) As AnzahlM,
       SUM(CASE WHEN s.gender = 'F' THEN 1 ELSE 0 END) as females,
       SUM(CASE WHEN s.gender = 'M' THEN 1 ELSE 0 END) as males
FROM Branch b LEFT JOIN
     Staff s
     ON b.BranchID = s.BranchFK AND s.position = 'Supervisor'
GROUP BY b.BranchID;

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