sql与另一个表格计算多个记录

Question

我在这里有两个表格。我想要的是在这两个表格内计算（添加）数量和平衡。但困难在于交易表中的两个account_no是相同的（A-102）。那么如何在transactions.account_id = account.account_no = A-102时将amount加到balance？

我所做的是：

select account_no, balance + (
           select t.amount 
           from transactions t 
           where t.account_no = 'A-222') 
    from b_account 

    where account_no = 'A-222'; 

这种方法仅适用A-305和A-222。 如果我写这样的，它不会工作..

select account_no, balance + (
           select t.amount 
           from transactions t 
           where t.account_no = (
                select t.account_no 
                from b_account ba, transactions t 
                where ba.account_no = t.account_no 
                )  
          ) 
from b_account 
where account_no = (select t.account_no 
        from b_account ba, transactions t 
        where ba.account_no = t.account_no); 

任何帮助的感谢！先进

Answer 1

您可以通过帐号group和sum所有金额，然后将结果加入帐户表。试试这个

with cte as 
(
select account_no, SUM(t.amount) amount 
from transactions t 
--where t.account_no = 'A-222' 
group by account_no 
) 

Select a.account_no, balance + coalesce(b.amount,0) new_balance 
from b_account a 
left outer join cte b on a.account_no = b.account_no 
--where a.account_no = 'A-222'