Database
[MySQL/HackerRank]Aggregation
문제 링크: https://www.hackerrank.com/domains/sql?filters%5Bsubdomains%5D%5B%5D=aggregation Solve SQL Code Challenges A special-purpose language designed for managing data held in a relational database. www.hackerrank.com Aggregation까지 다 풀고 나니 실버 4가 됐다. Median을 구하는 'Weather Observation Station 20' 문제 빼고는 평이한 난이도였다. -- Revising Aggregations - The Count Function SELECT COUNT(ID) FROM CITY WHERE POPULA..
