i have code for MySQL but i need to PostgreSQL. Can you help me convert from MySQL to PostgreSQL?
Create TRIGGER date_reservation
BEFORE INSERT ON reservation
FOR EACH ROW
BEGIN
IF
NEW.date_reservation IS NULL OR NEW.date_reservation = ''
THEN
SET NEW.date_reservation = NOW();
END IF
END
In Postgres, your first need to create a function:
CREATE FUNCTION date_reservation_function()
RETURNS trigger AS $$
BEGIN
IF NEW.date_reservation IS NULL OR NEW.date_reservation = '' THEN
NEW.date_reservation := NOW();
END IF;
RETURN NEW;
END$$ LANGUAGE 'plpgsql'
Then, you create a trigger that invokes the function:
CREATE TRIGGER date_reservation_trigger
BEFORE INSERT ON reservation
FOR EACH ROW
EXECUTE PROCEDURE date_reservation_function()
In both MySQL and Postgres, I would recommend that you simply do this using a default value:
create table date_reservation (
. . .
date_reservation timestamp default now(),
. . .
);
You can actually do something similar in MySQL.
