hackerrank Weather Observation Station 3

 

 

1) MOD(id, 2) = 0

 

1-1) 

SELECT city

FROM STATION

WHERE MOD(id, 2) = 0;

 

1-1) 결과

 

 

2) 중복 체크

 

2-1)

SELECT city

FROM STATION
WHERE MOD(id, 2) = 0

GROUP BY city;

 

2-1) 결과

 

 

SUCCESS!!