jspcal

也许用 git commit -F <file> 从文件中读取评论?

只需在联接表中减去列即可。当其中一个操作数为空时,算术运算的结果为空:

select a.Number, a.Event, a.Weight, a.Weight - b.Weight as DIFF
from a
left join b on a.Number = b.Number and a.Event = b.Event