c# - 如何确定sql server中的连续日期记录

Question

我有一个这样的数据结构：

ID     Status     Date
---    ------     ------------
1      I          2013-10-01
1      A          2013-10-02
1      A          2013-10-03
1      I          2013-10-04
1      I          2013-10-05
1      I          2013-10-06
1      A          2013-10-07
1      I          2013-10-08

我想确定有多少状态I是连续的。在这种情况下 3 (2013-10-04, 05 和 06)。

像这样的东西：

Status   ID   Total_consecutive
-------  ---  ------------------
A        1    2
I        1    3

提前致谢。

Answer 1

我相信这会给你正确的结果：

declare @t table
(
    ID INT,    
    [Status] CHAR(1),    
    [Date] DATE
);
insert @t (ID, [Status], [Date])
values (1, 'I', '2013-10-01'),
(1, 'A', '2013-10-02'),
(1, 'A', '2013-10-03'),
(1, 'I', '2013-10-04'),
(1, 'I', '2013-10-05'),
(1, 'I', '2013-10-05'),
(1, 'I', '2013-10-05'),
(1, 'I', '2013-10-06'),
(1, 'A', '2013-10-10')

;with a as
(
select ID, [Status], [Date], 
row_number() over (partition by id order by [Status], [Date])-
row_number() over (partition by id order by [Date], [Status]) rn1

from @t
)
select ID, [Status], min([Date]) Start, max([Date]) [End], 
           count(*) [Total_consecutive] 
from a
group by id, [Status], rn1
having count(*) > 1

结果：

ID  Status  Start       End         Total_consecutive
1   A       2013-10-02  2013-10-03  2
1   I       2013-10-04  2013-10-06  5