重叠日期范围sql的不同间隔

Question

我已经看到很多关于如何合并多个日期范围的查询 - 但是否有一个简单的查询来确定所有的时间间隔？

例如

start           end
2010-01-01      2010-01-31
2010-01-10      2010-02-10

我想显示所有不同的间隔 即

start           end
2010-01-01      2010-01-09
2010-01-10      2010-01-31
2010-02-01      2010-02-10

以上示例适用于 2 个日期范围 - 理想情况下，结果应适用于 n 个日期范围

Answer 1

检查以下代码。

首先展平开始和结束，并为它们每个添加“级别”。 级别是当时重叠范围的数量。 然后为每一行生成当前日期和 rext 日期之间的时间范围， 省略 level = 0 的行

with
a as (
  select "start" as date, 'S' as type from TBL
  union
  select "end" as date, 'E' as type from TBL
),
b as (
  select 
    date,
    sum(case when type = 'S' then 1 else -1 end)
        over(order by date
             rows between unbounded preceding and current row) as level,
    lead(date) over (order by  date) as next_date
  from a
)
select 
    date as start,
    (next_date - 1) as end
from b
where level > 0 // out of range
  and date <> next_date

运行这个：
https://www.db-fiddle.com/f/rgfTsAamaoujRaQy9FLtnQ/1