針對特定時間段內可用人員的Sql SELECT

Question

我有3個表格。第一個是人員名單：

表Personnel

Id_personnel   Name 
1     John 
2     Alice 
3     Tom 
4     Charles 
5     Ben 

二是與醫療休假表：

表Medical

Id_personnel   Start_date   End_date 
3     2012-08-02   2012-08-05 
2     2012-08-02   2012-08-15 
4     2012-10-04   2012-10-06 
2     2012-10-02   2012-10-15 
2     2012-09-20   2012-09-21 

三是節日休假表：

表Holiday

Id_personnel   Start_date   End_date 
3     2012-08-02   2012-08-05 
2     2012-02-02   2012-02-15 
5     2012-10-01   2012-10-05 

我有兩個事件日期：Symposium_start_date和Symposium_end_date（作爲變量），我想選擇所有Personnel.Id_personnel和Personnel.Name可用於研討會（未休病假或假期）。

在我的例子，如果Symposium_start_date = 2012-10-02和Symposium_end_date = 2012-10-06其結果必然是：

Id_personnel   Name 
1     John 
3     Tom 

（你可以看到愛麗絲和查爾斯都在休病假和Ben度假）

謝謝！

Answer 1

對於MS SQL服務器。

declare @start date = '2012-10-02', @end date = '2012-10-10' 

select personnel.* 
from personnel 
    left join holiday on personnel.Id_personnel = holiday.Id_personnel 
     and holiday.start_date<=@end 
     and holiday.end_date>=@start 
    left join medical on personnel.Id_personnel= medical.Id_personnel 
     and medical.start_date<=@end 
     and medical.end_date>=@start 
where holiday.Id_personnel is null 
and medical.Id_personnel is null 

Answer 2

這是一個僅用於醫療表的示例。您可以輕鬆地添加假日

declare @Symposium_start_date datetime 
declare @Symposium_end_date datetime 

set @Symposium_start_date = '2012-08-01' 
set @Symposium_end_date = '2012-08-04' 


select * 
from personel p left join medical m on p.Id_personel = m.Id_personel 
where (@Symposium_start_date > m.end_date) or (@Symposium_end_date<m.start_date) 

Answer 3

假設MS-SQL，類似於人，但已經顯示錶聯合在一起，和子查詢，顯示所有與研討會日期那些誰衝突 - 我認爲這是比較容易先寫 - 然後選擇所有沒有衝突的人。問候！

declare @Symposium_start_date date = '2012-10-02' 
declare @Symposium_end_date date = '2012-10-06' 

select * from Personnel P where p.Id_personnel not in (
    select Id_personnel from (
     select m.Id_personnel, m.Start_date, m.End_date 
     from Medical M 
     union 
     select h.Id_personnel, h.Start_date, h.End_date 
     from Holiday H 
    ) as Leave 
    where (Start_date between @Symposium_start_date and @Symposium_end_date) 
     or (End_date between @Symposium_start_date and @Symposium_end_date) 
     or (Start_date <= @Symposium_start_date and End_date >= @Symposium_end_date) 
)