hour 1

[ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค | SQL] ์ž…์–‘ ์‹œ๊ฐ ๊ตฌํ•˜๊ธฐ(1) (GROUP BY)

SQL ๊ณ ๋“์  Kit > GROUP BY > ์ž…์–‘ ์‹œ๊ฐ ๊ตฌํ•˜๊ธฐ(1)  ์ž…์–‘ ์‹œ๊ฐ ๊ตฌํ•˜๊ธฐ(1) Lv.2๋ณดํ˜ธ์†Œ์—์„œ๋Š” ๋ช‡ ์‹œ์— ์ž…์–‘์ด ๊ฐ€์žฅ ํ™œ๋ฐœํ•˜๊ฒŒ ์ผ์–ด๋‚˜๋Š”์ง€ ์•Œ์•„๋ณด๋ ค ํ•ฉ๋‹ˆ๋‹ค. 09:00๋ถ€ํ„ฐ 19:59๊นŒ์ง€, ๊ฐ ์‹œ๊ฐ„๋Œ€๋ณ„๋กœ ์ž…์–‘์ด ๋ช‡ ๊ฑด์ด๋‚˜ ๋ฐœ์ƒํ–ˆ๋Š”์ง€ ์กฐํšŒํ•˜๋Š” SQL๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์ด๋•Œ ๊ฒฐ๊ณผ๋Š” ์‹œ๊ฐ„๋Œ€ ์ˆœ์œผ๋กœ ์ •๋ ฌํ•ด์•ผ ํ•ฉ๋‹ˆ๋‹ค.   ์ฒซ ๋ฒˆ์งธ ํ’€์ด :     100์ -- ์ฝ”๋“œ๋ฅผ ์ž…๋ ฅํ•˜์„ธ์š”SELECT HOUR(DATETIME) AS HOUR, COUNT(*) AS 'COUNT'FROM ANIMAL_OUTSWHERE HOUR(DATETIME) >= 9 AND HOUR(DATETIME) HOUR(DATETIME)์œผ๋กœ ๊ตฌ๋ฃนํ™”ํ•ด์ฃผ์—ˆ์œผ๋ฏ€๋กœ WHERE ์ ˆ์„ ํ†ตํ•ด ์กฐ๊ฑด ๋ถ€์—ฌ