[SQL] 조건에 맞는 회원수 구하기

문제링크

https://school.programmers.co.kr/learn/courses/30/lessons/131535

프로그래머스

 

1. 핵심

• 특정 년도를 확인하는 방법
  • LIKE
  • DATE_FORMAT(col, "%Y")
  • YEAR(col)
• a 이상 b 이하
  • (col) BETWEEN a AND b

2. 코드(MySQL)

SELECT COUNT(USER_ID) AS USERS
FROM USER_INFO
WHERE JOINED LIKE "2021%" AND AGE BETWEEN 20 AND 29;

 

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select count(USER_ID) as USERS
from USER_INFO
where date_format(JOINED, "%Y") = 2021 and age between 20 and 29;

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select count(USER_ID) as USERS
from USER_INFO
where year(JOINED) = "2021" and age between 20 and 29;

3. 활용예제

SELECT date, temperature
FROM temperature_records
WHERE date BETWEEN '2024-01-01' AND '2024-01-15';