需要Sql查询方案

Question

Trans Id  Date       Description       Credit        Debit 
1         12/05/2009 Amount Deposited   1000          1000
2         15/05/2009 Amount withdrawn   -500          500
3         20/05/2009 Deposited          2000          2500
4         25/05/2009 Amount withdrawn   -1000         1500
                             1500

Trans ID是主键

我需要输出如下

Trans Id  Date         Description       Amount
1         12/05/2009   Amount Deposited  1000
2         15/05/2009   Amount withdrawn  500
3         20/05/2009   Deposited         2000
4         25/05/2009   Amount withdrawn  1000
                       balance         1500

需要Sql查询来生成输出

Answer 1

我认为这可以满足您的需求：

SELECT TransId, Date, Description, ABS(Credit) AS Amount
FROM transactions
UNION ALL
SELECT NULL, NULL, 'balance', SUM(Credit)
FROM transactions;

结果：

TransId  Date        Description       Amount
1        2009-05-12  Amount Deposited  1000            
2        2009-05-15  Amount Withdrawn  500             
3        2009-05-20  Deposited         2000            
4        2009-05-25  Amount Withdrawn  1000            
NULL     NULL        balance           1500            

Answer 2

您可以使用case语句查找最大值，使用abs来确保正数：

select  [trans id]
,       date
,       description
,       abs(case when credit > debit then credit else debit end) as Amount
from    YourTable

重新阅读你的问题，我怀疑这是你正在寻找的答案。请详细解释一下。