Re: [PATCH] Add pg_get_trigger_ddl() to retrieve the CREATE TRIGGER statement

On 2025-Oct-14, jian he wrote:

> select pg_get_trigger_ddl(-1, 'h');
> ERROR: relation with OID 4294967295 does not exist
>
> this error obviously is not good.
> we can follow the approach used by pg_get_viewdef(oid)

Hmm. For pg_get_viewdef() we have two functions:

{ oid => '1640', descr => 'select statement of a view',
proname => 'pg_get_viewdef', provolatile => 's', proparallel => 'r',
prorettype => 'text', proargtypes => 'text',
prosrc => 'pg_get_viewdef_name' },

{ oid => '1641', descr => 'select statement of a view',
proname => 'pg_get_viewdef', provolatile => 's', proparallel => 'r',
prorettype => 'text', proargtypes => 'oid', prosrc => 'pg_get_viewdef' },

one of which takes a 'name' reference the table, and the other takes
OID. I suspect this arrangement predates the 'regclass' business ...

git show 52200befd0^:src/backend/utils/adt/ruleutils.c

yep, it does. I think we wouldn't do it this way nowadays. I think the
choice to implement pg_get_trigger_ddl(regclass) is a good one.

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"Every machine is a smoke machine if you operate it wrong enough."
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