PostgreSQL

ยท SQL
1. ์›ํ•˜๋Š” ๋‚ ์งœ๋ณ„ ํ˜น์€ ๊ธฐ๊ฐ„๋ณ„๋กœ ์ž๋ฅด๊ธฐ Truncate์˜ ์ถ•์•ฝ ํ‘œํ˜„์ธ trunc๊ฐ€ ๋“ค์–ด๊ฐ„ ํ•จ์ˆ˜์ด๋‹ค. date_trunc ์›๋ž˜ ๋‹จ์–ด ๋œป ๊ทธ๋Œ€๋กœ ๋‚ ์งœ๋ฅผ ์ž˜๋ผ๋‚ธ๋‹ค, ์ ˆ์‚ฌํ•œ๋‹ค. ์ง๊ด€์ ์ด๋‹ค. date_trunc(์ ˆ์‚ฌ ๋‹จ์œ„, ์ ˆ์‚ฌ ๋Œ€์ƒ) ์ ˆ์‚ฌ ๋Œ€์ƒ ์œ„์น˜์— ๋‚ ์งœ ํ˜น์€ ์‹œ๊ฐ„ ๊ฐ’์ด ํ‘œํ˜„๋˜๋Š” ๋ฐ์ดํ„ฐ๋ฒ ์ด์Šค ํ•„๋“œ๋ช…์„ ์ž…๋ ฅํ•œ๋‹ค. (type timestamp, timestamp with time zone ๋˜๋Š” interval์˜ ๊ฐ’) ํ•ด๋‹น ๋‚ ์งœ๋ฅผ ์–ด๋А ์ •๋„์˜ ์ •๋ฐ€๋„๋กœ ์ชผ๊ฐค ๊ฒƒ์ธ์ง€ ๋‹จ์œ„๋ฅผ ์ง€์ •ํ•œ๋‹ค. (๋ฐ˜ํ™˜ ๊ฐ’๋„ ๋งˆ์ฐฌ๊ฐ€์ง€๋กœ type timestamp, time zone ๋˜๋Š” interval) date_trunc('year', timestamp) // ์—ฐ๋„๋ณ„ date_trunc('month', timestamp) // ์›”๋ณ„ date_..
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'PostgreSQL' ํƒœ๊ทธ์˜ ๊ธ€ ๋ชฉ๋ก