[해커랭크 SQL] Basic Select - Weather Observation Station 4

❓ Question

https://www.hackerrank.com/challenges/weather-observation-station-4

Weather Observation Station 4 | HackerRank

❗ Answer

SELECT COUNT(city)-COUNT(DISTINCT city)
    FROM station;

📌 Discussion

- COUNT로 레코드의 개수를 집계