๐Ÿ–ฅ๏ธ ์ฝ”๋”ฉํ…Œ์ŠคํŠธ/SQL

[ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค] [SQL] ์กฐ๊ฑด์— ๋งž๋Š” ๋„์„œ์™€ ์ €์ž ๋ฆฌ์ŠคํŠธ ์ถœ๋ ฅํ•˜๊ธฐ

rtw0202 2026. 2. 7. 20:58

1. ๋ฌธ์ œ ์„ค๋ช…

๋‹ค์Œ์€ ์–ด๋А ํ•œ ์„œ์ ์—์„œ ํŒ๋งค์ค‘์ธ ๋„์„œ๋“ค์˜ ๋„์„œ ์ •๋ณด(BOOK), ์ €์ž ์ •๋ณด(AUTHOR) ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ํ…Œ์ด๋ธ”์€ ๊ฐ ๋„์„œ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”๋กœ ์•„๋ž˜์™€ ๊ฐ™์€ ๊ตฌ์กฐ๋กœ ๋˜์–ด์žˆ์Šต๋‹ˆ๋‹ค.

AUTHOR ํ…Œ์ด๋ธ”์€ ๋„์„œ์˜ ์ €์ž์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”๋กœ ์•„๋ž˜์™€ ๊ฐ™์€ ๊ตฌ์กฐ๋กœ ๋˜์–ด์žˆ์Šต๋‹ˆ๋‹ค.

'๊ฒฝ์ œ' ์นดํ…Œ๊ณ ๋ฆฌ์— ์†ํ•˜๋Š” ๋„์„œ๋“ค์˜ ๋„์„œ ID(BOOK_ID), ์ €์ž๋ช…(AUTHOR_NAME), ์ถœํŒ์ผ(PUBLISHED_DATE) ๋ฆฌ์ŠคํŠธ๋ฅผ ์ถœ๋ ฅํ•˜๋Š” SQL๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ๊ฒฐ๊ณผ๋Š” ์ถœํŒ์ผ์„ ๊ธฐ์ค€์œผ๋กœ ์˜ค๋ฆ„์ฐจ์ˆœ ์ •๋ ฌํ•ด์ฃผ์„ธ์š”.

 

2. ์ถœ๋ ฅ ์˜ˆ์‹œ

 

3. ๋ฌธ์ œ ๋‹ต์•ˆ

SELECT
    b.book_id,
    a.author_name, 
    DATE_FORMAT(b.published_date, '%Y-%m-%d') AS published_date
FROM book b
JOIN author a
ON b.author_id = a.author_id
WHERE b.book_id IN (SELECT
                        b.book_id
                    FROM book b
                    WHERE b.category = '๊ฒฝ์ œ'
                    )
ORDER BY b.published_date ASC;