MySQL

https://inpa.tistory.com/entry/MYSQL-%F0%9F%93%9A-WITH-ROLLUP

https://gent.tistory.com/584#google_vignette

https://blog.naver.com/platinasnow/220400168429

https://autumn-irene.tistory.com/67

https://mizykk.tistory.com/121

https://jie0025.tistory.com/85

https://community.heartcount.io/ko/query-optimization-tips/

https://inpa.tistory.com/entry/MYSQL-%F0%9F%93%9A-JOIN-%EC%A1%B0%EC%9D%B8-%EA%B7%B8%EB%A6%BC%EC%9C%BC%EB%A1%9C-%EC%95%8C%EA%B8%B0%EC%89%BD%EA%B2%8C-%EC%A0%95%EB%A6%AC#inner_join

https://www.geeksforgeeks.org/sql-transactions/

https://m.blog.naver.com/regenesis90/222213959170

https://www.geeksforgeeks.org/sql-ddl-dql-dml-dcl-tcl-commands/

https://inpa.tistory.com/entry/MYSQL-%F0%9F%93%9A-%EC%9E%90%EB%A3%8C%ED%98%95-%ED%83%80%EC%9E%85-%EC%A2%85%EB%A5%98-%EC%A0%95%EB%A6%AC

https://dev-coco.tistory.com/55

https://github.com/good593/course_sql/blob/main/%EB%8D%B0%EC%9D%B4%ED%84%B0%20%EB%AA%A8%EB%8D%B8%EB%A7%81.md

https://inpa.tistory.com/entry/ERD-CLOUD-%E2%98%81%EF%B8%8F-ERD-%EB%8B%A4%EC%9D%B4%EC%96%B4%EA%B7%B8%EB%9E%A8%EC%9D%84-%EC%98%A8%EB%9D%BC%EC%9D%B8%EC%97%90%EC%84%9C-%EA%B7%B8%EB%A0%A4%EB%B3%B4%EC%9E%90

https://velog.io/@taekwon/MySQL-%EC%9E%90%EC%A3%BC-%EC%93%B0%EB%8A%94-MySQL-%EB%AA%85%EB%A0%B9%EC%96%B4-%EC%A0%95%EB%A6%AC