如何计算贷方和借方的余额?

How to calculate balance from credit and debit?

如何根据以下 txn_tbl table

每个客户 cust 的贷方 CRD 和借方 DEB 获取余额
SQL> SELECT * FROM txn_tbl;

CUS        AMT TXN_CDE
--- ---------- ----------
A          500 CRD
B          400 CRD
A          350 CRD
C          235 DEB
C          800 CRD
B          132 DEB
D          673 CRD

这是我试过的查询

SELECT cust, LAG(amt,1,0) OVER (PARTITION BY cust ORDER BY cust) "Bal"
 FROM 
(SELECT cust, SUM(amt)amt
 FROM txn_tbl
 GROUP BY cust, txn_cde
 ORDER BY 2);

如果您想要 运行 余额,您可以使用条件逻辑进行 window 求和:

select 
    t.*,
    sum(case when txn_cde = 'CRD' then amt else -amt end) 
        over(partition by cus order by id) running_balance
from mytable

为此,您需要一个可用于排序记录的列;我假设 id.

另一方面,如果您想要每个客户的总体余额(因此结果集中每个客户只有一个记录),您可以使用相同的聚合逻辑(并且不需要排序列):

select cus, sum(case when txn_cde = 'CRD' then amt else -amt end) balance
from mytable
group by cus

你可以把你的金额加起来。诀窍是让你的贷方(或借方,不清楚)为负数:

SELECT cust, Sum(CASE WHEN TXN_CODE = 'DEB' THEN -1 ELSE 1 END * amt) as
FROM txn_tbl 
GROUP BY cust