mysql 窗口函数 ROW_NUMBER、NTILE详解

CREATE TABLE `app_release` (
  `Id` int NOT NULL AUTO_INCREMENT COMMENT '主键id',
  `Platform` varchar(10) COLLATE utf8mb4_bin NOT NULL COMMENT '平台,ios,android',
  `Version` varchar(10) COLLATE utf8mb4_bin NOT NULL COMMENT '版本号',
  PRIMARY KEY (`Id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin COMMENT='app发版信息';

 select *  from
  (select *, ROW_NUMBER() OVER (partition by PLATFORM order by Version desc) as num from app_release) tmp
   where num = 1 

CREATE TABLE `test` (
  `id` int NOT NULL AUTO_INCREMENT,
  `value` decimal(10,2) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=14 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

SELECT
	* 
FROM
	( SELECT *, NTILE( 10 ) OVER ( ORDER BY `value` DESC ) AS _ntile FROM test ) a 
WHERE
	_ntile <= 7