[HackerRank/SQL] Revising Aggregations - The Sum Function

Problem. Revising Aggregations - The Sum Function

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Link.

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

Revising Aggregations - The Sum Function | HackerRank

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Description.

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

 

CITY 테이블

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Key Point. 

SELECT,

 

SUM,

 

WHERE,

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My Answer. 

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

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References.