为以下内容编写正确的SQL查询： - 我使用了查询？数据来自多个表

Question

我用过查询： -

select 
    employees.N, employees.ID, Date(Month) as m, count(*) as P,
    (FullOrHalfLeave) as FOH 
from 
    employees, leaveapplication, leaveapplicationdetails 
where 
    employees.ID = leaveapplication.ID 
    and leaveapplication.LeaveApplicationID = leaveapplicationdetails.Leave_Application_ID 
    and TypeOfLeave = 1 
    and LeaveStatus = 4 
    and employees.ID = 18 
group by 
    employees.ID,FOH 
order by 
    employee.N, FOH

我得到如下结果： -

N       ID      m       P         FOH
--------------------------------------
A       18      1       8          1
A       18      1       3          2
A       18      4       6          1
A       18      5       3          1
A       18      5       1          2
A       18      6       3          2
A       18      9       1          1
A       18      9       4          2

我想要这样的结果：

N       ID      m       Pad         FOH
----------------------------------------
A       18      1       9.5          -
A       18      4       6            -
A       18      5       3.5          -
A       18      6       1.5          -
A       18      9       3            -

Answer 1

你不需要返回FOH，只需这样做：

select employees.N, employees.ID, Date(Month) as m, SUM(1 / FullOrHalfLeave) as P

这样，如果FOH = 1，那么您将计算一天，如果FOH = 2您将计算半天。