如果其他日期介于两者之间，则将日期范围与单独的组分组

Question

我有一个 Table 这样的：

Specification    Date 
ADS              2020-09-04 00:00:00.000
ADS              2020-09-05 00:00:00.000
ADS              2020-09-06 00:00:00.000
AZR              2020-09-07 00:00:00.000
AZR              2020-09-08 00:00:00.000
ADS              2020-09-09 00:00:00.000
ADS              2020-09-10 00:00:00.000

我想要 select 开始日期和结束日期，并按规范对它们进行分组。所以我的输出应该是这样的：

Specification    Start                     End
ADS              2020-09-04 00:00:00.000   2020-09-06 00:00:00.000
AZR              2020-09-07 00:00:00.000   2020-09-08 00:00:00.000
ADS              2020-09-09 00:00:00.000   2020-09-10 00:00:00.000

我试过：

select
Specification, MIN(Date) as Start, MAX(Date) as End
from CUSTOMERS
group by Specification

但这并没有给出我想要的结果。有人有想法吗？

Answer 1

你可以试试下面的 - 这是一个间隙和孤岛问题

select col1, min(dateval) as start, max(dateval) as end
from
(
select *,row_number() over(order by dateval)-
row_number() over(partition by col1 order by dateval) as grp
from t
)A group by col1, grp

如果其他日期介于两者之间，则将日期范围与单独的组分组

Group Date ranges with separate groups if other date in between

sql

sql-server

gaps-and-islands