查找列中行的差异

问题描述

I want to create a new table where the difference of weight will be displayed as weight diff. for eg first day the difference is 0,so second day for the same id the weight should be like +.. for gain and - .. for loss

解决方法

你似乎想要lag()：

select t.*,(weight -
        lag(weight,1,weight) over (partition by id order by date)
       ) as weight_diff
from t;

你的图片真的很难看，所以我只使用了描述中给出的名字。