SQL 按行减去成本

Question

我有一个数据集

--City        Brand     Cost       Date
--Nashville   A         $100       11/14/2023
--Nashville   A         $125       11/15/2023

我想看

--City        Brand     Difference  Latest Date
--Nashville   A         $25         11/15/2023

提前致谢！

与

RankedCombination

分割完毕 是行号 <= 1

等等

Answer 1

以下 sql 在 Oracle 中给出了所需的结果：

select city,brand,difference,datecol 
from (select rownum as r,city,brand,
      cost - lead(cost) over (order by datecol desc) as difference, 
      datecol 
      from t1 order by datecol desc)
where r=1;