Question

我有以下数据：

Create Table #Temp
(
CallDate DateTime
)

Insert into #Temp
Select '2015-01-01'
Union
Select '2015-01-02'
Union
Select '2015-01-03'
Union
Select '2015-01-04'
Union
Select '2015-01-06'
Union
Select '2015-01-08'
Union
Select '2015-01-09'
Union
Select '2015-01-15'

我想要的是日期范围：

FromDate    ToDate
2015-01-01  2015-01-04
2015-01-06  2015-01-06
2015-01-08  2015-01-09
2015-01-15  2015-01-15

Answer 1

PostgreSQL语法，因为我现在没有办法在SQL Server上进行测试。原理很简单。减去row_number（）值的日期是连续日期的常量。您可以对常量进行分组。

with grouped_dates as (
  select call_date,
         (call_date - (row_number() over (order by call_date) || ' days')::interval)::date as group_date
  from temp
)
select min(call_date) as from_date, max(call_date) as to_date
from grouped_dates
group by group_date
order by min(call_date);

from_date     to_date
--
2015-01-01    2015-01-04
2015-01-06    2015-01-06
2015-01-08    2015-01-09
2015-01-15    2015-01-15

Answer 2

如果你有一个数字表，你可以做这样的事情（每个范围都有一个联合），虽然这很麻烦。

SELECT dateadd(day, number-1, '2015-01-01') as FinalDate
FROM numbers
WHERE number <= datediff(day, '2015-01-01', '2015-01-04') + 1

更好的选择可能是UDF（请参阅此处：https://stackoverflow.com/a/1378788/1324019）

CTE查询日期

2 个答案: