Re: Split daterange into sub periods

On 07/05/2018 08:30 AM, Hellmuth Vargas wrote:
>
> Hi
>
> select ($$[$$|| to_char(min(n.dato),'YYYY-MM-DD') || $$,$$ ||
> to_char(max(n.dato),'YYYY-MM-DD') || $$]$$)::daterange,
> daterange(min(n.dato)::date,max(n.dato)::date)
> from (
> select u.dato,anterior,(u.dato-anterior)::interval,sum(case when
> anterior is null or (u.dato -anterior)::interval='1 day'::interval  then
> 0 else 1 end) over(order by u.dato) as grupo
> from (
> select u.dato, lag(u.dato) over( order by u.dato) as anterior,
> lead(u.dato) over( order by u.dato)
> from (
> select * from generate_series(lower('[2018-01-01,
> 2018-01-31]'::daterange),upper('[2018-01-01, 2018-01-31]'::daterange),'1
> day'::interval) as a(dato)
> except
> (
> select generate_series(lower(a.dato),upper(a.dato),'1 day'::interval)
> from
> (values('[2018-01-04,2018-01-06]'::daterange),('[2018-01-09,2018-01-12]'::daterange),('[2018-01-18,2018-01-19]'::daterange))
> as a(dato)
>
> )
> ) as u order by u.dato
> ) as u
> ) as n
> group by grupo
> order by 1
>
>
>
>         daterange        |        daterange
> -------------------------+-------------------------
>  [2018-01-01,2018-01-04) | [2018-01-01,2018-01-03)
>  [2018-01-08,2018-01-09) | empty
>  [2018-01-14,2018-01-18) | [2018-01-14,2018-01-17)
>  [2018-01-21,2018-02-02) | [2018-01-21,2018-02-01)
> (4 rows)
>

Interesting but I am not sure this is working as the OP wants. If I am
following the excluded ranges from your query are:

[2018-01-04,2018-01-06]
[2018-01-09,2018-01-12]
[2018-01-18,2018-01-19]

From what I understand the OP wants, the returned periods should be:

[2018-01-01,2018-01-03]
[2018-01-07,2018-01-08]
[2018-01-13,2018-01-17]
[2018-01-20,2018-01-31]

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com