From: | Jian He <hejian(dot)mark(at)gmail(dot)com> |
---|---|
To: | pgsql-sql <pgsql-sql(at)lists(dot)postgresql(dot)org> |
Subject: | Does postgresql know the check condition is valid or not. or can check deduce from multiple conditions |
Date: | 2022-04-06 04:07:55 |
Message-ID: | CAMV54g2OxGKMyuUVwNM0LdDZsvM7XJVbe4WmVRMLNTZ5X1d0Gg@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-sql |
If the question is stupid, please tell me why.
postgresql - How to query check the constraint is valid or not - Stack
Overflow
<https://stackoverflow.com/questions/71746611/how-to-query-check-the-constraint-is-valid-or-not>
Postgres 14 | db<>fiddle (dbfiddle.uk)
<https://dbfiddle.uk/?rdbms=postgres_14&fiddle=8157a4c1823635980019f3bdb1fa6835>
CREATE TABLE emp (test_check int check ( test_check >1 and test_check
< 0 ));
alter table emp VALIDATE CONSTRAINT emp_test_check_check;```
select * from pg_constraint where conname = 'emp_test_check_check';
Even with the above mentioned step, does postgresql know above check
constraint condition always false.
another similar question:
can postgresql deduce from
CREATE TABLE emp1 (test_check int check ( test_check >1 and test_check > 10
));
to
CREATE TABLE emp1 (test_check int check ( test_check > 10 ));
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2022-04-06 04:10:25 | Re: Does postgresql know the check condition is valid or not. or can check deduce from multiple conditions |
Previous Message | Steve Midgley | 2022-04-05 15:14:57 | Re: Histogram question. |