CREATE OR REPLACE TRIGGER LAST_CHANGE_TRIG_PR_ITEMOPTION
BEFORE INSERT OR UPDATE OR DELETE
    ON PR_ITEMOPTION
FOR EACH ROW

DECLARE
    item_id NUMBER(18);
    style_id NUMBER(18);

BEGIN
    -- 1. get item_id
    IF (DELETING) THEN
        item_id := :OLD.PR_ITEM_ID;
    ELSE
        item_id := :NEW.PR_ITEM_ID;
    END IF;

    -- 2. get style_id
    SELECT
        PR_ITEM.PR_STYLE_ID
    INTO
        style_id
    FROM
        PR_ITEM
    WHERE
        PR_ITEM.PR_ITEM_ID = item_id;

    -- 3. set last_modified
    UPDATE
        PR_STYLE style
    SET
        style.LAST_MODIFIED = SYSDATE
    WHERE
        style.PR_STYLE_ID = style_id;
END;
/