Re: Adding custom constraints on a postgres database

"David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
> On Thu, Feb 29, 2024, 11:10 Debraj Manna <subharaj(dot)manna(at)gmail(dot)com> wrote:
>> Can someone let me know if there is a way I can add some custom
>> rules/constraints on a Postgres database?
>>
>> For example, all tables in a database should have a primary key specified.
>> If someone is trying to violate the rules specified then the SQL command
>> should fail.

> https://www.postgresql.org/docs/current/event-trigger-definition.html

When/where are you expecting to enforce this? If you prohibit the
common pattern of CREATE TABLE followed sometime later by ALTER TABLE
ADD PRIMARY KEY, you will soon regret that.

I think you might be better served by writing a lint-like thing
that can be run periodically to look through the system catalogs
for policy violations. Rejecting SQL commands on-the-fly will be
expensive, as well as painful to work with.

regards, tom lane