一、给查询结果添加序号列的方法

1、方法一

set @counter=0;
SELECT @counter:=@counter+1 as rank,t.s_score FROM score  t

2、方法二

SELECT @a:= @a +1 as rank,t.s_score FROM score t,(select @a:=0) a 	

3、方法三

SELECT   @i:=@i+1 as i,   -- 不保留空缺排名
@k:=(case when @score=a.sum_score then @k else @i end) as rank,   -- 保留空缺排名，数值重复时序号保持一致
@score:=a.sum_score as score     
FROM (select 语句)a,(排序初始化) b

二、书写格式

select * from (select 语句)a,(排序初始化) b

三、参考链接

1、https://www.cnblogs.com/northern-light/p/8494711.html
2、https://www.pianshen.com/article/54351348701/