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Problem Solving/SQL

[ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค] MYSQL.SUM, MAX, MIN

by DevIseo 2022. 4. 14.

1. ์ตœ๋Œ€๊ฐ’  ๊ตฌํ•˜๊ธฐ

https://programmers.co.kr/learn/courses/30/lessons/59415

 

์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต - ์ตœ๋Œ“๊ฐ’ ๊ตฌํ•˜๊ธฐ

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_INTAKE๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””

programmers.co.kr

SELECT MAX(DATETIME) AS '์‹œ๊ฐ„'
FROM ANIMAL_INS

2. ์ตœ์†Ÿ๊ฐ’ ๊ตฌํ•˜๊ธฐ

https://programmers.co.kr/learn/courses/30/lessons/59038

 

์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต - ์ตœ์†Ÿ๊ฐ’ ๊ตฌํ•˜๊ธฐ

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_INTAKE๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””

programmers.co.kr

SELECT MIN(DATETIME) AS '์‹œ๊ฐ„'
FROM ANIMAL_INS

3. ๋™๋ฌผ ์ˆ˜ ๊ตฌํ•˜๊ธฐ

https://programmers.co.kr/learn/courses/30/lessons/59406

 

์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต - ๋™๋ฌผ ์ˆ˜ ๊ตฌํ•˜๊ธฐ

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_INTAKE๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””

programmers.co.kr

SELECT COUNT(*)
FROM ANIMAL_INS;

 

4. ์ค‘๋ณต ์ œ๊ฑฐํ•˜๊ธฐ

https://programmers.co.kr/learn/courses/30/lessons/59408

 

์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต - ์ค‘๋ณต ์ œ๊ฑฐํ•˜๊ธฐ

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_INTAKE๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””

programmers.co.kr

SELECT COUNT(DISTINCT NAME)
FROM ANIMAL_INS
WHERE NAME IS NOT NULL;

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