[Hacker Rank_MySQL]문제 풀이#The Report

SQL > Basic Join > The Report

The Report | HackerRank

Ketty gives Eve a task to generate a report containing three columns: Name, Grade and Mark. Ketty doesn't want the NAMES of those students who received a grade lower than 8. The report must be in descending order by grade -- i.e. higher grades are entered first. If there is more than one student with the same grade (8-10) assigned to them, order those particular students by their name alphabetically. Finally, if the grade is lower than 8, use "NULL" as their name and list them by their grades in descending order. If there is more than one student with the same grade (1-7) assigned to them, order those particular students by their marks in ascending order.

Write a query to help Eve.

 

Note

Print "NULL"  as the name if the grade is less than 8.

빨간 글씨는 내가 문제를 풀 때 중요하다고 생각한 부분이다.

 

 

SELECT
    CASE
        WHEN G.GRADE > 7
        THEN S.NAME
        ELSE NULL
    END AS NAME,
    G.GRADE, S.MARKS
FROM STUDENTS S
JOIN GRADES G
ON (S.MARKS BETWEEN G.MIN_MARK AND G.MAX_MARK)
ORDER BY G.GRADE DESC, S.NAME ASC, S.MARKS ASC