如何使用postgres窗口功能在会计软件中计算余额

select t.*, sum(“In”-“Out”) over(order by id) as balance
from tbl t
order by id

小提琴： http

**://sqlfiddle.com/#!15/97dc5/2/0**

考虑更改列名“ In” /“ Out”，这样您就不必在引号中加上引号了。（它们是保留字）

如果只需要一位客户（customer_id = 2）：

select t.*, sum("In"-"Out") over(order by id) as balancefrom tbl twhere customer_id = 2order by id

如果您的查询要跨越多个客户，并且您希望与每个客户重新开始保持平衡，则可以使用：

select t.*, sum("In"-"Out") over( partition by customer_id order by customer_id, id ) as balance_by_custfrom tbl torder by customer_id, id