同一分支同一季度数计算

Question

我需要添加的是当员工职称X在SAME分支内切换到不同的职位（Y或Z）时，修改他们在该新职称（Y或Z）中所用季度的总FTE ）。

所以逻辑是：

对于位置X到Y

IF [Position Start Date] is between [Q2 start date] AND [Q2 end date]
and [Employee Title] of [Employee ID] was X and is now Y
THEN [Total FTE calculated] = (((([Position Start Date] - [Quarter Start Date])/[Days in Quarter]) * [Total FTE]) + ((([Quarter End Date] - [Position Start Date])/[Days in Quarter]) * [Total FTE]) * 0.5)

对于位置X到Z

AND IF [Position Start Date] is between [Q2 start date] AND [Q2 end date]
AND [Employee Title] of [Employee ID] was X and is now Z
THEN [Total FTE calculated] = ([Position Start Date] - [Quarter Start Date])/[Days in Quarter]) * [Total FTE])

ELSE [Total FTE Calculated] = [Total FTE] * 1
END

正如您所看到的，我缺少一些SQL运算符的知识来正确执行此操作。您将提供的任何帮助将不胜感激！ 拜托，谢谢！

Answer 1

粗略的草图，日期算术在不同的DBMS供应商之间有很大不同，所以我使用了你的表达式。我已经将变量：new_emplyee_title用于新标题。

update Employees
    set [Total FTE calculated] = case when :new_emplyee_title = Y 
                                      then [ expression for Y ]
                                      else [ expression for Z ] 
                                 end
where [Position Start Date] between [Q2 start date] AND [Q2 end date]
  and [Employee Title] = X
  and :new_emplyee_title in (Y,Z);

如果您使用DBMS支持触发器，这就像在更新触发器中一样。