iseunghan
8-3) ํ”„๋ก์‹œ์™€ ์—ฐ๊ด€๊ด€๊ณ„ ๊ด€๋ฆฌ - ์˜์†์„ฑ ์ „์ด(CASCADE), orphanremoval(๊ณ ์•„)