postgresql create trigger function code example

Example 1: example of trigger in postgresql

-- Trigger to update donatiom count in donor table whenever
-- A new donation is made by that person

CREATE or REPLACE FUNCTION increase_count()
RETURNS TRIGGER
AS
$$
BEGIN
	UPDATE donor SET dcount = dcount + 1 WHERE did = NEW.did;
END
$$
LANGUAGE plpgsql;



CREATE TRIGGER update_donation_count AFTER INSERT ON donation
FOR EACH ROW
EXECUTE PROCEDURE increase_count();

Example 2: postgres trigger insert into another table

CREATE OR REPLACE FUNCTION function_copy() RETURNS TRIGGER AS
$BODY$
BEGIN
    INSERT INTO
        table2(id,name)
        VALUES(new.id,new.name);

           RETURN new;
END;
$BODY$
language plpgsql;