mysql排名

mysql排名問題
使用mysql內置函數
row_number() over (order by val) as 'row_number':1,2,3,4,5,6
rank() over (order by val) as 'rank':1,2,3,3,5,6
dense_rank() over (order by val) as 'dense_rank':1,2,3,3,4,5

1.row_number() over (order by val) as 'row_number'：1，2，3，4，5，6···
例如：
創建這樣一個表chengji:

現在按照score從高到低不重複排名

select *,row_number over (order by score desc) as 'row_number'
from chengji;

2.rank() over (order by val) as 'rank':1，2，3，3，5，6···
例如創建一個表chengji

select *,rank() over (order by score desc) as 'rank'
from chengji;

3.dense_rank() over (order by val) as 'dense_rank':1,2,3,3,4,5,6···
例如創建一個表chengji

select *,dense_rank() over (order by score desc) as 'dense_rank'
from chengji;