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๊ด€๋ฆฌ ๋ฉ”๋‰ด

๋ชฉ๋ก๐Ÿ“ Coding Test/MySQL (26)

Data Science LAB

[MySQL]ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค ์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต 14

๋ฌธ์ œ ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE ๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””, ์ƒ๋ฌผ ์ข…, ๋ณดํ˜ธ ์‹œ์ž‘์ผ, ๋ณดํ˜ธ ์‹œ์ž‘ ์‹œ ์ƒํƒœ, ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ๋‚˜ํƒ€๋ƒ…๋‹ˆ๋‹ค. ์ž…์–‘ ๊ฒŒ์‹œํŒ์— ๋™๋ฌผ ์ •๋ณด๋ฅผ ๊ฒŒ์‹œํ•˜๋ ค ํ•ฉ๋‹ˆ๋‹ค. ๋™๋ฌผ์˜ ์ƒ๋ฌผ ์ข…, ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ์•„์ด๋”” ์ˆœ์œผ๋กœ ์กฐํšŒํ•˜๋Š” SQL๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์ด๋•Œ ํ”„๋กœ๊ทธ๋ž˜๋ฐ์„ ๋ชจ๋ฅด๋Š” ์‚ฌ๋žŒ๋“ค์€ NULL์ด๋ผ๋Š” ๊ธฐํ˜ธ๋ฅผ ๋ชจ๋ฅด๊ธฐ ๋•Œ๋ฌธ์—, ์ด๋ฆ„์ด ์—†๋Š” ๋™๋ฌผ์˜ ์ด๋ฆ„์€ "No name"์œผ๋กœ ํ‘œ์‹œํ•ด ์ฃผ์„ธ์š”. ์˜ˆ์‹œ ๋ฌธ์ œ ํ’€์ด SELECT ANIMAL_TYPE..

๐Ÿ“ Coding Test/MySQL 2022. 2. 20. 12:45
[MySQL] ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค ์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต 13(๋™๋ช… ๋™๋ฌผ ์ˆ˜ ์ฐพ๊ธฐ)

๋ฌธ์ œ ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE ๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””, ์ƒ๋ฌผ ์ข…, ๋ณดํ˜ธ ์‹œ์ž‘์ผ, ๋ณดํ˜ธ ์‹œ์ž‘ ์‹œ ์ƒํƒœ, ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ๋‚˜ํƒ€๋ƒ…๋‹ˆ๋‹ค. ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ ์ด๋ฆ„ ์ค‘ ๋‘ ๋ฒˆ ์ด์ƒ ์“ฐ์ธ ์ด๋ฆ„๊ณผ ํ•ด๋‹น ์ด๋ฆ„์ด ์“ฐ์ธ ํšŸ์ˆ˜๋ฅผ ์กฐํšŒํ•˜๋Š” SQL๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์ด๋•Œ ๊ฒฐ๊ณผ๋Š” ์ด๋ฆ„์ด ์—†๋Š” ๋™๋ฌผ์€ ์ง‘๊ณ„์—์„œ ์ œ์™ธํ•˜๋ฉฐ, ๊ฒฐ๊ณผ๋Š” ์ด๋ฆ„ ์ˆœ์œผ๋กœ ์กฐํšŒํ•ด์ฃผ์„ธ์š”. ์˜ˆ์‹œ ๋ฌธ์ œ ํ’€์ด SELECT NAME, COUNT(*) FROM ANIMAL_INS WHERE NAME IS NOT NU..

๐Ÿ“ Coding Test/MySQL 2022. 2. 19. 15:10
[MySQL] ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค ์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต 12(๋ฃจ์‹œ์™€ ์—˜๋ผ ์ฐพ๊ธฐ)

๋ฌธ์ œ ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE ๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””, ์ƒ๋ฌผ ์ข…, ๋ณดํ˜ธ ์‹œ์ž‘์ผ, ๋ณดํ˜ธ ์‹œ์ž‘ ์‹œ ์ƒํƒœ, ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ๋‚˜ํƒ€๋ƒ…๋‹ˆ๋‹ค. ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ ์ค‘ ์ด๋ฆ„์ด Lucy, Ella, Pickle, Rogan, Sabrina, Mitty์ธ ๋™๋ฌผ์˜ ์•„์ด๋””์™€ ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ์กฐํšŒํ•˜๋Š” SQL ๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์˜ˆ์‹œ ๋ฌธ์ œ ํ’€์ด SELECT ANIMAL_ID, NAME, SEX_UPON_INTAKE FROM ANIMAL_INS WHERE N..

๐Ÿ“ Coding Test/MySQL 2022. 2. 18. 13:10
[MySQL]ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค ์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต 11

๋ฌธ์ œ ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE ๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””, ์ƒ๋ฌผ ์ข…, ๋ณดํ˜ธ ์‹œ์ž‘์ผ, ๋ณดํ˜ธ ์‹œ์ž‘ ์‹œ ์ƒํƒœ, ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ๋‚˜ํƒ€๋ƒ…๋‹ˆ๋‹ค. ๋ณดํ˜ธ์†Œ์— ๋Œ์•„๊ฐ€์‹  ํ• ๋จธ๋‹ˆ๊ฐ€ ๊ธฐ๋ฅด๋˜ ๊ฐœ๋ฅผ ์ฐพ๋Š” ์‚ฌ๋žŒ์ด ์ฐพ์•„์™”์Šต๋‹ˆ๋‹ค. ์ด ์‚ฌ๋žŒ์ด ๋งํ•˜๊ธธ ํ• ๋จธ๋‹ˆ๊ฐ€ ๊ธฐ๋ฅด๋˜ ๊ฐœ๋Š” ์ด๋ฆ„์— 'el'์ด ๋“ค์–ด๊ฐ„๋‹ค๊ณ  ํ•ฉ๋‹ˆ๋‹ค. ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ ์ด๋ฆ„ ์ค‘, ์ด๋ฆ„์— "EL"์ด ๋“ค์–ด๊ฐ€๋Š” ๊ฐœ์˜ ์•„์ด๋””์™€ ์ด๋ฆ„์„ ์กฐํšŒํ•˜๋Š” SQL๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์ด๋•Œ ๊ฒฐ๊ณผ๋Š” ์ด๋ฆ„ ์ˆœ์œผ๋กœ ์กฐํšŒํ•ด์ฃผ์„ธ์š”. ๋‹จ, ์ด๋ฆ„์˜ ๋Œ€์†Œ๋ฌธ์ž๋Š” ..

๐Ÿ“ Coding Test/MySQL 2022. 2. 17. 12:39
[MySQL] ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค ์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต10

๋ฌธ์ œ ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE ๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””, ์ƒ๋ฌผ ์ข…, ๋ณดํ˜ธ ์‹œ์ž‘์ผ, ๋ณดํ˜ธ ์‹œ์ž‘ ์‹œ ์ƒํƒœ, ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ๋‚˜ํƒ€๋ƒ…๋‹ˆ๋‹ค. ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋™๋ฌผ์ด ๋ช‡ ๋งˆ๋ฆฌ ๋“ค์–ด์™”๋Š”์ง€ ์กฐํšŒํ•˜๋Š” SQL ๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์˜ˆ์‹œ ๋ฌธ์ œํ’€์ด SELECT COUNT(ANIMAL_ID) AS 'count' FROM ANIMAL_INS ๋™๋ฌผ์˜ ์ˆ˜๋ฅผ ๊ตฌํ•˜๋Š” ๋ฌธ์ œ์ด๋ฏ€๋กœ COUNT()ํ•จ์ˆ˜๋ฅผ ์‚ฌ์šฉํ–ˆ๋‹ค. ANIMAL_ID ๋˜๋Š” *์„ ์‚ฌ์šฉํ•˜๋ฉด ๋™๋ฌผ์˜ ์ˆ˜๋ฅผ ๊ตฌํ•  ์ˆ˜ ์žˆ๋‹ค!

๐Ÿ“ Coding Test/MySQL 2022. 2. 16. 12:58
[MySQL] ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค ์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต 9

๋ฌธ์ œ ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE ๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””, ์ƒ๋ฌผ ์ข…, ๋ณดํ˜ธ ์‹œ์ž‘์ผ, ๋ณดํ˜ธ ์‹œ์ž‘ ์‹œ ์ƒํƒœ, ์ด๋ฆ„, ์„ฑ๋ณ„ ๋ฐ ์ค‘์„ฑํ™” ์—ฌ๋ถ€๋ฅผ ๋‚˜ํƒ€๋ƒ…๋‹ˆ๋‹ค. ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๊ฐ€์žฅ ๋จผ์ € ๋“ค์–ด์˜จ ๋™๋ฌผ์€ ์–ธ์ œ ๋“ค์–ด์™”๋Š”์ง€ ์กฐํšŒํ•˜๋Š” SQL ๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์˜ˆ์‹œ ๋ฌธ์ œ ํ’€์ด SELECT MIN(DATETIME) AS "์‹œ๊ฐ„" FROM ANIMAL_INS ์กฐํšŒํ•œ ๋ฐ์ดํ„ฐ์˜ ์ปฌ๋Ÿผ๋ช…์„ ๋ฐ”๊พธ๋ ค๋ฉด SELECT [์ปฌ๋Ÿผ๋ช…] AS "๋ฐ”๊พธ๊ณ ์‹ถ์€ ์ปฌ๋Ÿผ๋ช…" ๊ฐ€์žฅ ๋นจ๋ฆฌ ๋“ค์–ด์˜จ ์‹œ๊ฐ„์„ ๊ตฌํ•˜๋Š” ๋ฌธ์ œ์ด๋ฏ€๋กœ MIN()ํ•จ..

๐Ÿ“ Coding Test/MySQL 2022. 2. 15. 15:52