SQL的4种排名函数，附图表说明

函数名	说明
row_number	行号
rank	排名
dense_rank	稠密的排名
ntile	按百分比分组排名

SELECT
  score
  ,ROW_NUMBER() OVER(ORDER BY score desc) AS a_row_number
  ,RANK()       OVER(ORDER BY score desc) AS a_rank
  ,DENSE_RANK() OVER(ORDER BY score desc) AS a_dense_rank
  ,NTILE(3)     OVER(ORDER BY score desc) AS a_ntile3
  ,NTILE(4)     OVER(ORDER BY score desc) AS a_ntile4
FROM (
  SELECT 99 AS score UNION ALL
  SELECT 98 AS score UNION ALL
  SELECT 98 AS score UNION ALL
  SELECT 97 AS score
) a;

score	row number	rank	dense rank	ntile 3	ntile 4
99	1	1	1	1	1
98	2	2	2	1	2
98	3	2	2	2	3
97	4	4	3	3	4

ntile逻辑如下

score	percentage	ntitle 3	ntitle 4
99	0	1 [0,33)	1 [0,25)
98	25	1 [0,33)	2 [25,50)
98	50	2 [33,67)	3 [50,75)
97	75	3 [67,100)	4 [75,100)