mysql 排序设置序号取出某条数据所在序号（排名）

 SELECT a.orderNum AS NRankingNum  FROM  (SELECT (@i:=@i+1) AS orderNum, pkCode,fkUser,fkSchool,sUserName,nScore  FROM  `TbPhysicalTestReport` ,  (SELECT @i:=0) AS i WHERE fkSchool='0001' AND  sSemester = '上学期' AND DATE_FORMAT(tCreate,'%Y') = '2022' ORDER BY nScore DESC) a WHERE a.fkUser = '0Z6H';