यहाँ एक कार्यशील समाधान है:
CREATE TEMPORARY TABLE t_employees (
first_name TEXT,
mid_name TEXT,
last_name TEXT,
fullname TEXT
);
CREATE OR REPLACE FUNCTION set_fullname()
RETURNS TRIGGER AS $$
BEGIN
NEW.fullname = NEW.first_name || ' ' || NEW.mid_name || ' ' || NEW.last_name;
RETURN NEW;
END;
$$ language 'plpgsql';
CREATE TRIGGER set_fullname_trigger
BEFORE INSERT OR UPDATE ON t_employees
FOR EACH ROW
EXECUTE PROCEDURE set_fullname();
SET client_min_messages TO 'debug';
INSERT INTO t_employees VALUES ('fname1', 'mname1', 'lname1');
SELECT * FROM t_employees;
UPDATE t_employees SET first_name = 'updated-first-name';
SELECT * FROM t_employees;