동순위 처리는 어찌 하나요?
 - 3등까지 뽑아야 하는데 3등이 여러명인 경우
 - 내 앞에 두명을 뽑아야 하는데 3명이 동순위인 경우

-- 1. 테스트용 테이블 생성 --
CREATE TABLE race_fish
AS
SELECT 1 user_index, 9 fish_size, '13:00' create_date
UNION ALL SELECT 1, 8, '12:00'
UNION ALL SELECT 1, 9, '11:00'
UNION ALL SELECT 2, 6, '13:00'
UNION ALL SELECT 2, 7, '12:00'
UNION ALL SELECT 2, 8, '11:00'
UNION ALL SELECT 3, 8, '13:00'
UNION ALL SELECT 3, 7, '12:00'
UNION ALL SELECT 3, 6, '11:00'
UNION ALL SELECT 4, 7, '13:00'
UNION ALL SELECT 5, 6, '11:00'
UNION ALL SELECT 6, 6, '11:01'
UNION ALL SELECT 7, 5, '11:00'
UNION ALL SELECT 8, 4, '11:00'
UNION ALL SELECT 9, 3, '11:00'
;

-- 2. 순위 구하기 --
SELECT user_index
     , fish_size
     , create_date
     , rk
  FROM (SELECT user_index
             , fish_size
             , create_date
             , @rk := @rk + 1 AS rk
             , CASE user_index WHEN @My_ID THEN @My_rk := @rk END
          FROM (SELECT b.user_index
                     , b.fish_size
                     , MIN(b.create_date) create_date
                  FROM (SELECT user_index
                             , MAX(fish_size) fish_size
                          FROM race_fish
                         GROUP BY user_index
                        ) a
                 INNER JOIN race_fish b
                    ON a.user_index = b.user_index
                   AND a.fish_size  = b.fish_size
                 GROUP BY b.user_index, b.fish_size
                 ORDER BY fish_size DESC, create_date ASC, user_index ASC
                ) a
             , (SELECT @rk    := 0  -- 순위
                     , @My_rk := 0  -- 내 순위
                     , @My_ID := 7  -- 내 ID
                ) b
        ) a
 WHERE rk IN (1, 2, 3, @My_rk-2, @My_rk-1, @My_rk, @My_rk+1, @My_rk+2)
;