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๊ณผ๋ชฉII SQL ๊ธฐ๋ณธ ๋ฐ ํ™œ์šฉ 2์žฅ - 1์ ˆ ํ‘œ์ค€ ์กฐ์ธ
SQLD 2021. 5. 24. 18:13

FROM ์ ˆ์˜ JOIN ํ˜•ํƒœ (์ถ”๊ฐ€๋œ ์„ ํƒ ๊ธฐ๋Šฅ์œผ๋กœ ํ…Œ์ด๋ธ” ๊ฐ„์˜ JOIN ์กฐ๊ฑด์„ FROM์ ˆ์—์„œ ๋ช…์‹œ์ ์œผ๋กœ ์ •์˜ํ•  ์ˆ˜ ์žˆ๊ฒŒ ๋˜์—ˆ๋‹ค.) -INNER JOIN -NATURAL JOIN -USIN ์กฐ๊ฑด์ ˆ -ON ์กฐ๊ฑด์ ˆ -CROSS JOIN -OUTER JOIN โ€ปSQL server์˜ ๊ฒฝ์šฐ ON ์กฐ๊ฑด์ ˆ๋งŒ ์ง€์›ํ•˜๊ณ  NATURAL JOIN๊ณผ USING ์„ ์ง€์›ํ•˜์ง€ ์•Š๋Š”๋‹ค. 1)INNER JOIN - ๋‚ด๋ถ€ JOIN์ด๋ผ๊ณ  ํ•˜๋ฉฐ JOIN ์กฐ๊ฑด์—์„œ ๋™์ผํ•œ ๊ฐ’์ด ์žˆ๋Š” ํ–‰๋งŒ ๋ฐ˜ํ™˜ํ•œ๋‹ค. - INNER JOIN ํ‘œ์‹œ๋Š” ๊ทธ๋™์•ˆ WHERE ์ ˆ์—์„œ ์‚ฌ์šฉํ•˜๋˜ JOIN ์กฐ๊ฑด์„ FROM์ ˆ์—์„œ ์ •์˜ํ•˜๊ฒ ๋‹ค๋Š” ํ‘œ์‹œ์ด๋ฏ€๋กœ ๋’ค์— ON, USING ๊ผญ ์จ์ฃผ์–ด์•ผ ํ•จ - ์˜ˆ์‹œ) SELECT EMP.DEPTNO, EMPNO, ENAME, DNAME FROM..