Re: How to generate the order if you know the next item for each item?
| От | Rockdale Green |
|---|---|
| Тема | Re: How to generate the order if you know the next item for each item? |
| Дата | |
| Msg-id | CAArxxWh0=hFNLGQ-BODXjqhFu2vJdg0+haKAEbqq6ph-H4A5Og@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: How to generate the order if you know the next item for each item? (Tony Shelver <tshelver@gmail.com>) |
| Список | pgsql-sql |
Thanks, I do not need functions at this time but will keep that in mind in the future.
On Thu, Aug 5, 2021 at 10:33 AM Tony Shelver <tshelver@gmail.com> wrote:
We have some ordered processing that we need to do that can involve reading through 10s of thousands of records, with a lot of conditional processing. We use functions almost exclusively for this, returning a table of results.On Tue, 3 Aug 2021 at 18:22, David G. Johnston <david.g.johnston@gmail.com> wrote:On Tue, Aug 3, 2021 at 8:40 AM Rockdale Green <rockdale.green@gmail.com> wrote:can I do it in one query?Yes.It might be just very simple and I have tried but somehow I am blocked.The feature you need is a recursive CTE (WITH RECURSIVE clause). It requires an initial row (which in this case is task 3, the only task that doesn't appear as a task_order value) and a query to retrieve the next row(s) using the information available in the previous iteration.The documentation and/or online resources can walk you through the specifics.David J.
В списке pgsql-sql по дате отправления: