[hackerrank] Revising Aggregations - The Sum Function

[hackerrank] Prepare > SQL > Aggregation > > Revising Aggregations - The Sum Function

 

[문제]

 

Query the total population of all cities in CITY where District is California.

Input Format

The CITY table is described as follows: 

[MYSQL]

 

 

[ORCALE]

select sum(population)
from city
where district = 'California';