[MySQL] Hackerrank SQL 연습문제 (4)

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SQL Übung - Hackerrank

• SQL 문제 풀이를 통한 SQL 연습

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Japan Population

• 17/11/2021
• 🔗 문제 링크

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

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Population Density Difference

• 17/11/2021
• 🔗 문제 링크

SELECT
    MAX(POPULATION) - MIN(POPULATION)
FROM
    CITY;

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The Blunder

• 17/11/2021
• 🔗 문제 링크

SELECT
    CEIL(AVG(Salary) - AVG(REPLACE(Salary, 0, '')))
FROM
    EMPLOYEES;

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Top Earners

• 17/11/2021
• 🔗 문제 링크

SELECT
    months * salary,
    COUNT(1)
FROM
    Employee
GROUP BY
    months * salary
ORDER BY 
    months * salary DESC
LIMIT 
    1;

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Weather Observation Station 2

• 17/11/2021
• 🔗 문제 링크

SELECT
    ROUND(SUM(LAT_N), 2),
    ROUND(SUM(LONG_W), 2)
FROM
    STATION;

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Weather Observation Station 13

• 17/11/2021
• 🔗 문제 링크

SELECT
    TRUNCATE(SUM(LAT_N), 4)
FROM
    STATION
WHERE
    LAT_N > 38.7880 
    AND LAT_N < 137.2345
    

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Weather Observation Station 14

• 17/11/2021
• 🔗 문제 링크

SELECT
    TRUNCATE(MAX(LAT_N), 4)
FROM
    STATION
WHERE
    LAT_N < 137.2345

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Weather Observation Station 15

• 17/11/2021
• 🔗 문제 링크

SELECT
    ROUND(LONG_W, 4)
FROM
    STATION
WHERE
    LAT_N < 137.2345
ORDER BY 
    LAT_N DESC 
LIMIT 1;

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Weather Observation Station 16

• 17/11/2021
• 🔗 문제 링크

SELECT
    ROUND(MIN(LAT_N), 4)
FROM
    STATION
WHERE
    LAT_N > 38.7780;

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Weather Observation Station 17

• 17/11/2021
• 🔗 문제 링크

SELECT
    ROUND(LONG_W, 4)
FROM
    STATION
WHERE
    LAT_N > 38.7780
ORDER BY
    LAT_N 
LIMIT
    1;

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