sql查询相同列的差异

Question

这是我的数据库,显示我的销售借记.此处列类型取0作为到期金额,1作为付款金额.我正在尝试计算剩余的到期日.

code Name   due bill date        type
--------------------------------------
113  ABC    30  9   2018-04-03    0
113  ABC    7   10  2018-04-03    0
113  ABC    20  11  2018-04-05    1
114  XYZ    25  25  2018-05-06    0

当从37中减去20时,这是我想要的表格

code Name      due 
------------------
113 ABC        17
114 XYZ        25

我用过这个查询

select code, name,SUM(amount) from Debit group by code, name, type

什么是上述问题的正确查询？提前致谢

Answer 1

你想要这样的东西:

select code, name,
       sum(case when type = 0 then due else - due end) as due
from t
where type in (0, 1)
group by code, name;