SQLD · 모의고사 8회 · 50번

다음 스크립트의 실행이 모두 정상적으로 완료되었다. 마지막 SELECT 문의 조회 결과는?

CREATE TABLE ITEM_STOCK (PROD_ID NUMBER, QUANTITY NUMBER);
INSERT INTO ITEM_STOCK VALUES (401, 55);
INSERT INTO ITEM_STOCK VALUES (401, 25);
INSERT INTO ITEM_STOCK VALUES (402, 80);
SAVEPOINT SP_FIRST;
DELETE FROM ITEM_STOCK WHERE QUANTITY < 30;
SAVEPOINT SP_KEEP;
INSERT INTO ITEM_STOCK VALUES (401, 15);
UPDATE ITEM_STOCK SET QUANTITY = QUANTITY + 10 WHERE PROD_ID = 401;
SAVEPOINT SP_LAST;
DELETE FROM ITEM_STOCK WHERE PROD_ID = 401 AND QUANTITY < 30;
ROLLBACK TO SAVEPOINT SP_KEEP;
INSERT INTO ITEM_STOCK VALUES (401, 20);
COMMIT;

SELECT SUM(QUANTITY) FROM ITEM_STOCK WHERE PROD_ID = 401;