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์˜ค๋Š˜์˜ ๋ช…์–ธ
" ์ฒœ์žฌ๋Š” 1%์˜ ์˜๊ฐ๊ณผ 99%์˜ ๋•€์ด๋‹ค. "
- ํ† ๋งˆ์Šค ์—๋””์Šจ (๋ฏธ๊ตญ ๋ฐœ๋ช…๊ฐ€, ์‚ฌ์—…๊ฐ€)
์˜คํ”ฝ (OPIC) ๋ณด๊ธฐ ์ „์— ๊ผญ ๋ด์•ผ ํ•  ๊ฟ€ํŒ & ์ „๋žต1. ์นœ๊ทผํ•œ ์ž๊ธฐ์†Œ๊ฐœ ์ค€๋น„ํ•ด๊ฐ€๊ธฐ๋„์ž…๋ถ€ + ๋ณธ๋ฌธ + ๋งˆ๋ฌด๋ฆฌ ํ˜•์‹์œผ๋กœ ์ค€๋น„ํ•˜๊ธฐ (๋„์ž…๋ถ€) ๋‹น์‹ ๊ณผ ์ด์•ผ๊ธฐ๋ฅผ ๋‚˜๋ˆ„๊ฒŒ ๋˜์–ด ๊ธฐ์ฉ๋‹ˆ๋‹ค.Hi, Ava. My name is Dain, but you can call me D. It's nice to be speaking with you. (๋ณธ๋ฌธ1)awesomepossum.tistory.com ์˜คํ”ฝ ์‹œํ—˜๋ฃŒ๋Š” ๋ถ€๊ฐ€์„ธ ํฌํ•จ 84,000์›์œผ๋กœ ๋น„์‹ผ ํŽธ์ด๋‹ค.IH๋ฅผ ๋ฐ›์•„์„œ AL ๋ชฉํ‘œ๋กœ ์žฌ์ ‘์ˆ˜๋ฅผ ํ–ˆ๋‹ค.๋ฐœํ™”๋Ÿ‰์„ ๋Š˜๋ฆฌ๋Š” ๊ฒƒ๋ณด๋‹ค ๋ฌธ์ œ๋‹น 1๋ถ„ 30์ดˆ, ๋‹ต๋ณ€์„ ์ผ์ฐ ๋๋งˆ์น˜๊ณ  ํ‡ด์‹ค ํ•˜๋Š” ๊ฒƒ์ด ๋‚ซ๋‹ค๋Š” ์ƒ๊ฐ์„ ํ–ˆ๋‹ค. ๋‚ด๊ฐ€ ๋Š๋‚€ ์ ์„ ๋‚จ๊ฒจ๋ณด๋ ค๊ณ  ํ•œ๋‹ค. 1. ์‹œํ—˜ ์ ‘์ˆ˜ ์‹œ ์œ ์˜์‚ฌํ•ญ์‹œํ—˜์ ‘์ˆ˜ ํ•  ๋•Œ [์‹œํ—˜์žฅ์†Œ]๋ฅผ ๋จผ์ € ์„ ํƒ ํ›„ [์‹œํ—˜์‹œ๊ฐ„]์„ ์„ ..
๐Ÿ“‘ 1. ๋ฌธ์ œ์„ค๋ช…โŒ 2. ์‹คํŒจํ•œ ์‹œ๋„์œ„์น˜ํ‹€๋ฆฐ๋ถ€๋ถ„๋งž๋Š” ์ฟผ๋ฆฌ์„ค๋ช…SELECTAVERAGEAVG()ํ‰๊ท ๊ตฌํ•˜๋Š” ํ•จ์ˆ˜AVERAGE()๊ฐ€ ์•„๋‹ˆ๊ณ AVG()์ž„ YEAR(YM)YEAR(YM) AS `YEAR`๋ณ„์นญ ์จ์•ผ ํ•จ์ปฌ๋Ÿผ๋ช… YEAR๋กœ ์ถœ๋ ฅ ROUND(AVG(PM_VAL1),3) ROUND(AVG(PM_VAL1),2)์†Œ์ˆ˜์…‹์งธ์ž๋ฆฌ์—์„œ ๋ฐ˜์˜ฌ๋ฆผํ•˜๋ ค๋ฉด ๋‘˜์งธ์ž๋ฆฌ๊นŒ์ง€ ๊ฒฐ๊ณผ๊ฐ’์ด ๋‚˜ํƒ€๋‚˜์•ผ ํ•˜๋‹ˆ๊นŒROUND(์ปฌ๋Ÿผ๋ช…, 2)๋กœ ํ•ด์•ผ ํ•จWHERELocation2 IS '์ˆ˜์›'Location2 = '์ˆ˜์›'IS๋Š” NULL ๊ฐ’๊ณผ์˜ ๋น„๊ต์—์„œ ๋งŒ ์‚ฌ์šฉ๋จORDER BYYEAR(YM)YEARSQL์˜ ์‹คํ–‰์ˆœ์„œ๋Š”ORDER BY์ ˆ์ด ๊ฐ€์žฅ๋งˆ์ง€๋ง‰์— ์‹คํ–‰๋˜๊ธฐ ๋•Œ๋ฌธ์—ALIAS ๋ช…์œผ๋กœ ์จ์ค˜๋„ ๋œ๋‹ค๊ผญ ๋ณ„์นญ ์จ์•ผํ•˜๋Š” ๊ฑด ์•„๋‹˜ SELECT YEAR(YM) AS YEAR,..
โœ… ๋ฌธ์ œ(77*1) + (76*2) + (75*3) + ... + (1*77)๋ฅผ ๊ณ„์‚ฐํ•˜์—ฌ ๊ฒฐ๊ณผ๋ฅผ ์ถœ๋ ฅํ•˜์‹œ์˜ค.โœ… ์ถ”๋ก  ๊ณผ์ •- ์ผ๋‹จ (a*b)+ ๊ตฌ๊ฐ„์ด ๋ฐ˜๋ณต๋˜๋ฉด์„œ ๋ˆ„์ ํ•ฉ์„ ๊ตฌํ•˜๋Š” ๋ฌธ์ œ์ด๋ฏ€๋กœ for๋ฌธ์„ ์‚ฌ์šฉํ•ด์ฃผ๋ฉด ๋œ๋‹ค.a๋Š” 77๋ถ€ํ„ฐ ์‹œ์ž‘ํ•ด์„œ 1์”ฉ ๊ฐ์†Œํ•˜๊ณ b๋Š” 1๋ถ€ํ„ฐ ์‹œ์ž‘ํ•ด์„œ 77๊นŒ์ง€ ์ฆ๊ฐ€ํ•˜๋Š” ํ˜•ํƒœ์ด๋‹ค.-> ์ด๊ฑด ๋”ฐ๋กœ b๋ณ€์ˆ˜๋ฅผ ์„ ์–ธํ•˜์ง€ ์•Š๊ณ  for๋ฌธ ์ดˆ๊ธฐ๊ฐ’์„ i=1๋กœ ์„ค์ • ํ•ด์ฃผ๋ฉด ๋œ๋‹ค. ์—ฌ๊ธฐ์„œ ์„ ์–ธํ•ด ์ค„ ์ˆ˜ ์žˆ๋Š” ๋ณ€์ˆ˜๋Š” ๋‘๊ฐœ์ด๋‹ค.1. a = 77;// 77๋ถ€ํ„ฐ ์‹œ์ž‘ํ•ด์„œ 1์”ฉ ๊ฐ์†Œ์‹œ์ผœ์ค„ ๋ณ€์ˆ˜ a๋ฅผ ์„ ์–ธ2. result = 0;// result ๋ณ€์ˆ˜์—๋Š” ๋ˆ„์ ํ•ฉ์„ ๋‹ด์•„์„œ ๋งˆ์ง€๋ง‰์— ๊ฒฐ๊ณผ ์ถœ๋ ฅํ•ด์ฃผ๋Š” ๋ฐ ์“ธ ๊ฒƒ์ด๋‹ค.(77*1) + ๊ตฌ๊ฐ„์ด ๊ณ„์† ๋ฐ˜๋ณต๋˜๊ธฐ ๋•Œ๋ฌธ์— ๋ฐ˜๋ณต๋ฌธ for๋ฌธ์œผ๋กœ ๋ฌถ์–ด์„œ ๊ณ„์‚ฐํ•ด์ค€๋‹ค.a ๊ธฐ์ค€์œผ๋กœ 77๋ถ€ํ„ฐ 1๊นŒ..
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