Re: Document behaviour of failed sub queries
| От | David G. Johnston |
|---|---|
| Тема | Re: Document behaviour of failed sub queries |
| Дата | |
| Msg-id | CAKFQuwbxG+U9CHJJJ3a6KLr91xS0D1LVuFLjRdBN_Zkc1+tp_w@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Document behaviour of failed sub queries ("David G. Johnston" <david.g.johnston@gmail.com>) |
| Список | pgsql-docs |
On Mon, Jun 28, 2021 at 8:40 AM David G. Johnston <david.g.johnston@gmail.com> wrote:
On Mon, Jun 28, 2021 at 8:34 AM PG Doc comments form <noreply@postgresql.org> wrote:For example:
UPDATE table1 SET status='expired' WHERE id in (SELECT wrong_id IN table2)
This will update every row in table1if wrong_id doesn't exist, ignoring the
ERROR: column "wrong_id" does not exist from the subquery.The subquery never provokes that error by virtue of the fact it is a subquery. It's only if you run that as a standalone query do you see the error. This is because correlated subqueries are a thing (and, yes, they are documented).
I may have mis-read your email...the behavior I describe is usually what prompts these kinds of questions but your example doesn't actually fit the pattern. I find it hard to believe that what you describe is really happening...though usually with IN clauses the presence of NULLs can confound things.
You should put together a self-contained reproducer script and post it as a bug report once you've confirmed it produces the problem you describe while using psql and a current version of PostgreSQL.
David J.
В списке pgsql-docs по дате отправления: