Question

首先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说明。

我想算一下，每个分支机构都有多少名担任职位主管的女性和男性。

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
=＆GT;缺少B002,0,0

但我没有得到ID为'B002'的分支，它有ANzahlFSuperv = 0和ANzahlMSuperv = 0.所以它没有超级监督者。那么如何得到这个结果？

解决方案必须在视图中，以便如何获取此BranchID。

我尝试了一切但没有价值。

希望你们能解雇我！

谢谢！

Answer 1

为什么要为此使用视图？只需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;

SQL外部联接视图

1 个答案: