mySQL 将关系排序为下一个更高的数字

Question

Rank with Ties 正常工作，除了第一个记录总是丢失，无论它是如何获取的。试图对从低到高进行排名。

SELECT x.*, 
COUNT(*) AS myRank 
FROM myTablename x 
JOIN myTablename y 
ON x.number > y.number 
GROUP BY id  
ORDER BY myRank 

很高兴地说，经过长时间的努力，以下修订按预期工作!

SELECT x.*, 
Count(y.id)+1 AS myRank
FROM myTablename x 
LEFT JOIN myTablename y 
ON (x.number > y.number) 
GROUP BY x.id 
ORDER BY myRank

结果:

ID  #   Rank
A  -50  1
B  -40  2
C  -40  2
D  -30  4
E  -30  4

将“=”添加到...ON x.number >= y.number ...获得并列排名，除了并列记录排名到下一个更高的数字。

ID  #   Rank
A  -50  1
B  -40  3
C  -40  3
D  -30  5
E  -30  5

Ranking High-to-low with ON x.number <= y.number 做同样的事情。

Answer 1

这是一个没有自连接但使用变量的版本。它很可能也更快:

select id, points, rank from (
select
t.*,
@rownum := @rownum + 1,
@rank := if(@prev_points = points, @rank, @rownum) as rank,
@prev_points := points
from
test t,
(select @rank:=0, @rownum:=0, @prev_points) var_init
order by points desc
)sq

• 看到它在 sqlfiddle 中实时运行