Laravel migrate error near BEGIN on trigger PostgreSQL - php

Question

I have made database trigger in mysql and in laravel it is working fine, however when I moved to postgresql I am getting error:
SQLSTATE[42601]: Syntax error: 7 ERROR: syntax error at or near "BEGIN"
(I am new using postgresql btw)
Here is the code I've made in migration:
DB::unprepared('CREATE TRIGGER histories_insert AFTER INSERT ON packets FOR EACH ROW
BEGIN
IF new.status = "pending" THEN
insert into `histories` (`packet_id`, `message`, `created_at`, `updated_at`) VALUES (new.id, "Barang berhasil di buat", now(), now());
END IF;
END');
I really got confused about it. Hope someone can help me :)

Answer 1

The syntax and structure in mysql and postgre is different, in Postgres we have to write the trigger function (procedure) first then we called it in the body of our trigger
so after
FORE EACH ROW
There should be an
when event __type_of_event__
and then we call our trigger function
execute procedure __procedure_name__
Take a look at the doc about trigger here
and trigger procedure here
Noted that when event is optional, and the name of your field inside procedure should be change into plain text, or wrap it with double quotes (if it mixed with capital letter)
Don't worry about the version of documentation, postgresql trigger is consistent across versions, hope this helps!

Answer 2

You need to make it into a procedure:
From the docs:
PostgreSQL only allows the execution of a user-defined function for the triggered action. The standard allows the execution of a number of other SQL commands, such as CREATE TABLE, as the triggered action. This limitation is not hard to work around by creating a user-defined function that executes the desired commands.
DB::unprepared('CREATE TRIGGER histories_insert
AFTER INSERT ON packets
FOR EACH ROW
EXECUTE PROCEDURE that_procudure_you_wrote_with_that_content(new)');

Answer 3

As mentioned by Erdi, The syntax, and structure in MySQL is different than postgres.here is how you can write your migration for postgres Database:
CREATE OR REPLACE FUNCTION histories_insert()
RETURNS TRIGGER AS $$
BEGIN
IF NEW.status = 'pending' THEN
INSERT INTO histories (packet_id, message, created_at, updated_at)
VALUES (NEW.id, 'Barang berhasil di buat', NOW(), NOW());
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER histories_insert
AFTER INSERT ON packets
FOR EACH ROW
EXECUTE FUNCTION histories_insert();