percent_rank

percent_rank

윈도우 파티션 안에서 행의 상대 순위(즉 백분위수, percentile)를 반환하는 윈도우 함수예요.

출처: 문서

본문

구문(Syntax)

별칭(Alias): percentRank (대소문자 구분)

percent_rank ()
  OVER ([[PARTITION BY grouping_column] [ORDER BY sorting_column]
        [RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING]] | [window_name])
FROM table_name
WINDOW window_name as ([PARTITION BY grouping_column] [ORDER BY sorting_column] RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)

기본이면서 필수인 윈도우 프레임 정의는 RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING이에요. 윈도우 함수 구문에 대한 자세한 내용은 윈도우 함수 - 구문을 참고하세요.

예시(Example)

쿼리(Query)

CREATE TABLE salaries
(
    `team` String,
    `player` String,
    `salary` UInt32,
    `position` String
)
Engine = Memory;

INSERT INTO salaries FORMAT Values
    ('Port Elizabeth Barbarians', 'Gary Chen', 195000, 'F'),
    ('New Coreystad Archdukes', 'Charles Juarez', 190000, 'F'),
    ('Port Elizabeth Barbarians', 'Michael Stanley', 150000, 'D'),
    ('New Coreystad Archdukes', 'Scott Harrison', 150000, 'D'),
    ('Port Elizabeth Barbarians', 'Robert George', 195000, 'M'),
    ('South Hampton Seagulls', 'Douglas Benson', 150000, 'M'),
    ('South Hampton Seagulls', 'James Henderson', 140000, 'M');

쿼리(Query)

SELECT player, salary,
       percent_rank() OVER (ORDER BY salary DESC) AS percent_rank
FROM salaries;

응답(Response)

   ┌─player──────────┬─salary─┬───────percent_rank─┐
1. │ Gary Chen       │ 195000 │                  0 │
2. │ Robert George   │ 195000 │                  0 │
3. │ Charles Juarez  │ 190000 │ 0.3333333333333333 │
4. │ Michael Stanley │ 150000 │                0.5 │
5. │ Scott Harrison  │ 150000 │                0.5 │
6. │ Douglas Benson  │ 150000 │                0.5 │
7. │ James Henderson │ 140000 │                  1 │
   └─────────────────┴────────┴────────────────────┘

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