On 7/26/21 9:55 AM, Alban Hertroys wrote:
On 26 Jul 2021, at 17:52, Alban Hertroys <haram...@gmail.com> wrote:
Something like this:
with recursive foo (id, parent, children_ids) as (
select id, parent, null::text
from tree t
where not exists (
select 1 from tree c where c.parent = t.id
)
union all
select t.id, t.parent
, f.id || case f.children_ids when '' then '' else ',’ end ||
f.children_ids
from foo f
join tree t on f.parent = t.id
where f.parent <> 0
;
Almost, the null::text in the initial select should of course be '’ in your
case, and a unicode quote slipped into the last string of that case statement.
Alban Hertroys
--
If you can't see the forest for the trees,
cut the trees and you'll find there is no forest.
well actually I find this closer to the target.
with recursive kids (founder, firstoff, descendant )
as (select parent as founder, id as firstoff, id::text
from tree
where parent = 0
union all
select k.firstoff, t.id, t.id::text
from kids k join tree t on k.firstoff = t.parent
)
select founder, array_agg(descendant) as descendants
from kids group by founder
order by founder;
founder | descendants
---------+-------------------------------
0 | {273}
273 | {274,275,277}
275 | {280}
277 | {278}
280 | {281}
281 | {282,290}
282 | {283,284,285,286,287,288,289}
290 | {291,292,293,294,295}
(8 rows)
