add Trigger

CREATE OR REPLACE FUNCTION log_last_name_changes()
    RETURNS TRIGGER AS
$BODY$
BEGIN
    IF NEW.last_name <> OLD.last_name THEN
    INSERT INTO ht_salarycomponent_audit(ht_salarycomponent_audit_id, ad_client_id, ad_org_id, createdby, updatedby,
                ht_salarycomponent_id, first_name, last_name, changed_on)
                VALUES (get_uuid(), OLD.ad_client_id, OLD.ad_org_id, OLD.createdby, OLD.updatedby,
                OLD.ht_salarycomponent_id, OLD.first_name, OLD.last_name, now());

            END IF;
        RETURN NEW;
END;
$BODY$ LANGUAGE plpgsql;

CREATE TRIGGER last_name_changes
    BEFORE UPDATE
    ON ht_salarycomponent
    FOR EACH ROW
    EXECUTE PROCEDURE log_last_name_changes();