查找具有开始日期和结束日期的记录未涵盖的时间间隔

Question

我有一张费用记录表 (f_fee_item)，如下所示：

Fee_Item_ID    int
Fee_Basis_ID   int
Start_Date     date
End_Date       date

（删除不相关的列）

假设相同 Fee_Basis_ID 的记录不会重叠。

我需要在提供的@Query_Start_Date 和@Query_End_Date 之间找到每个Fee_Basis_ID 的费用记录中每个空白的开始日期和结束日期。我需要这些数据来计算未收取费用的所有期间的应计费用。

如果给定的 Fee_Basis_ID 根本没有费用记录，我还需要查询返回记录（如果有帮助，Fee_Basis_ID 是 D_Fee_Basis.Fee_Basis_ID 的外键）。

例如：

@Query_Start_Date = '2011-01-01'
@Query_Start_Date = '2011-09-30'

D_Fee_Basis：

F_Fee_Item
1
2
3

F_Fee_Item：

Fee_Item_ID  Fee_Basis_ID  Start_Date  End_Date
1            1             2011-01-01  2011-03-31
2            1             2011-04-01  2011-06-30
3            2             2011-01-01  2011-03-31
4            2             2011-05-01  2011-06-30

要求的结果：

Fee_Basis_ID   Start_Date  End_Date
1              2011-07-01  2011-09-30
2              2011-04-01  2011-04-30
2              2011-07-01  2011-09-30
3              2011-01-01  2011-09-30

几天来，我一直在尝试不同的自联接以使其正常工作，但没有成功。

请帮忙！！

Answer 1

这是一个解决方案：

declare @Query_Start_Date date= '2011-01-01' 
declare @Query_End_Date date = '2011-09-30' 

declare @D_Fee_Basis table(F_Fee_Item int)
insert @D_Fee_Basis values(1) 
insert @D_Fee_Basis values(2) 
insert @D_Fee_Basis values(3) 

declare @F_Fee_Item table(Fee_Item_ID int, Fee_Basis_ID int,Start_Date date,End_Date date)
insert @F_Fee_Item values(1,1,'2011-01-01','2011-03-31') 
insert @F_Fee_Item values(2,1,'2011-04-01','2011-06-30') 
insert @F_Fee_Item values(3,2,'2011-01-01','2011-03-31')
insert @F_Fee_Item values(4,2,'2011-05-01','2011-06-30')

;with a as
(-- find all days between Start_Date and End_Date
select @Query_Start_Date d
union all 
select dateadd(day, 1, d)
from a
where d <  @Query_end_Date
), b as
(--find all unused days
select a.d, F_Fee_Item Fee
from a, @D_Fee_Basis Fee
where not exists(select 1 from @F_Fee_Item where a.d between Start_Date and End_Date and Fee.F_Fee_Item = Fee_Basis_ID)
),
c as
(--find all start dates
select d, Fee, rn = row_number() over (order by fee, d) from b 
where not exists (select 1 from b b2 where dateadd(day,1, b2.d) = b.d and b2.Fee= b.Fee)
),
e as
(--find all end dates
select d, Fee, rn = row_number() over (order by fee, d) from b 
where not exists (select 1 from b b2 where dateadd(day,-1, b2.d) = b.d and b2.Fee= b.Fee)
)
--join start dates with end dates
select c.Fee Fee_Basis_ID, c.d Start_Date, e.d End_Date from c join e on c.Fee = e.Fee and c.rn = e.rn
option (maxrecursion 0)

结果链接： https://data.stackexchange.com/stackoverflow/q/114193/