HACKERRANK 7일차

Revising Aggregations - The Count Function

SELECT COUNT(NAME)
FROM CITY
WHERE POPULATION > 100000;

Revising Aggregations - The Sum Function

SELECT SUM(POPULATION)
FROM CITY
WHERE DISTRICT = 'California';

Revising Aggregations - Averages

SELECT AVG(POPULATION)
FROM CITY
WHERE DISTRICT = 'California';