[HackerRank/SQL] Aggregation - Japan Population

Problem. Aggregation - Japan Population

---

Link.

https://www.hackerrank.com/challenges/japan-population/problem?utm_campaign=challenge-recommendation&utm_medium=email&utm_source=24-hour-campaign 

Japan Population | HackerRank

---

Description.

Query the sum of the populations for all Japanese cities in CITY.

 

CITY 테이블

---

Key Point. 

SELECT,

 

SUM,

 

WHERE,

---

My Answer. 

SELECT SUM(POPULATION)
FROM CITY
WHERE COUNTRYCODE = 'JPN';

---

References.