๋ณธ๋ฌธ ๋ฐ”๋กœ๊ฐ€๊ธฐ

innerJoin1

[๐Ÿ“š sql ๋ฌธ๋ฒ•์„ ๊ณต๋ถ€ํ•˜์ž ๐Ÿ“š] JOIN(INNER ,LEFT, RIGHT, FULL, NATURAL... SQL์„ ์ด์šฉํ• ๋•Œ ๋‘๊ฐœ์˜ ํ…Œ์ด๋ธ”์„ ํ•ฉ์ณ์„œ ๋ฐ์ดํ„ฐ๋ฅผ ์กฐํšŒํ•˜๊ณ  ์‹ถ์„๋•Œ๊ฐ€ ์žˆ๋‹ค! ๊ทธ๋•Œ ์“ฐ์ด๋Š”๊ฒƒ์ด ๋ฐ”๋กœ JOIN์ด๋‹ค. ์˜ค๋Š˜์€ JOIN์— ๋Œ€ํ•ด ์•Œ์•„๋ณด์ž! JOIN์€ ๋‘ ๊ฐœ ์ด์ƒ์˜ ํ…Œ์ด๋ธ”์—์„œ ๋ฐ์ดํ„ฐ๋ฅผ ๊ฒ€์ƒ‰ํ•˜๊ฑฐ๋‚˜ ๊ฒฐํ•ฉํ•˜๋Š” ๋ฐ ์‚ฌ์šฉ๋˜๋Š” ํ‚ค์›Œ๋“œ์ž…๋‹ˆ๋‹ค. JOIN์„ ์‚ฌ์šฉํ•˜๋ฉด ํ…Œ์ด๋ธ” ๊ฐ„์˜ ๊ด€๊ณ„๋ฅผ ํ™œ์šฉํ•˜์—ฌ ๋ฐ์ดํ„ฐ๋ฅผ ํšจ๊ณผ์ ์œผ๋กœ ์—ฐ๊ฒฐํ•  ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. ๊ฐ€์žฅ ์ผ๋ฐ˜์ ์ธ JOIN ์ข…๋ฅ˜๋Š” INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN ๋“ฑ์ด ์žˆ์Šต๋‹ˆ๋‹ค. ์ด ์ค‘์—์„œ INNER JOIN์€ ๊ฐ€์žฅ ๊ธฐ๋ณธ์ ์ธ JOIN ์œ ํ˜•์ด๋ฉฐ, ๋‹ค๋ฅธ JOIN ์œ ํ˜•์€ ์ด๋ฅผ ๊ธฐ๋ฐ˜์œผ๋กœ ํ™•์žฅ๋˜์—ˆ์Šต๋‹ˆ๋‹ค. INNER JOIN INNER JOIN ์‚ฌ์šฉ๋ฐฉ๋ฒ• SELECT * FROM ํ…Œ์ด๋ธ”1 INNER JOIN ํ…Œ์ด๋ธ”2 ON ํ…Œ์ด๋ธ”1.์—ด =.. 2023. 4. 18.