代码杂谈-SQL中的rank&row_number函数

时间:2021-07-27 04:51:19

两个函数细节记不住. 写个例子备注一下.

 select 
no, name, score
, rank() over(partition by no order by score asc) rk1
, rank() over(partition by no order by score desc) rk2
, row_number() over(partition by no order by score asc) rn1
, row_number() over(partition by no order by score desc) rn2

from  values 
 (1,'a',1), (1,'a', null),
 (1, 'b',2), (1, 'b',-2), (1, 'b',1)
 t (no, name, score)
;

结果

no name score rk1 rk2 rn1 rn2
1 b 2 5 1 5 1
1 a 1 3 2 3 2
1 b 1 3 2 4 3
1 b -2 2 4 2 4
1 a N 1 5 1 5