join 1
JOIN

โ“JOIN SELECT A.๋ณ€์ˆ˜, A.๋ณ€์ˆ˜ from AJOIN BON A.๋ณ€์ˆ˜ = B.๋ณ€์ˆ˜WHERE B.๋ณ€์ˆ˜ ~~  โ“LEFT JOIN SELECT A.๋ณ€์ˆ˜, A.๋ณ€์ˆ˜ from ALEFT JOIN BON A.๋ณ€์ˆ˜ = B.๋ณ€์ˆ˜WHERE B.๋ณ€์ˆ˜ ~~~  JOIN๊ณผ LEFT JOIN ๋“ฑ ์ข…๋ฅ˜๊ฐ€ ๋‹ค์–‘ํ–ˆ๋‹ค. ์œ„์™€ ๊ฐ™์ด ์•„์ฃผ ๊ฐ„๋‹จํ•˜๊ฒŒ ์ •๋ฆฌํ–ˆ์ง€๋งŒ ๋‹ค์Œ์— ์กฐ๊ธˆ ๋” ๊ณต๋ถ€ํ•ด์„œ LEFT JOIN, RIGHT JOIN๊ณผ ๊ฐ™์ด ๊ฐ๊ฐ์ด ์˜๋ฏธํ•˜๋Š” ๊ฒƒ์„ ์ž์„ธํžˆ ์ •๋ฆฌํ•ด ๋ณผ ๊ฒƒ์ด๋‹ค. * JOIN, ON, WHERE์„ ์‚ฌ์šฉํ•˜์—ฌ JOIN๋ฌธ์„ ํ•ด๊ฒฐํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค.   ๋‹ค์Œ์— ๋” ์ž์„ธํžˆ ๋Œ์•„์˜ค๊ฒ ๋‹ค -!
โ˜๏ธ์ •๋ฆฌ/โ„๏ธSQL 2022.02.06
1
๋”๋ณด๊ธฐ

ํ‹ฐ์Šคํ† ๋ฆฌํˆด๋ฐ”