php - 在 mysql 中使用条件选择 SUM()

Question

假设我有

SELECT `Type`, `Originating Country Code`,`Originating Currency Code`, SUM(`Principal Amount`) as Total 
FROM `colab` 
WHERE (`Destination Country Code`='PH' 
    AND `Destination Currency Code`='PHP'
    AND `Type` = 'PAID') || (`Destination Country Code`='PH' 
    AND `Destination Currency Code`='USD'
    AND `Type`= 'PAID')
    GROUP BY `Type`

工作正常并返回 true 请看下面

country_code | Currency_Code  |   Type    |  Principal

=======================================================
| PH         |   PHP          |    PAID   |    200
=======================================================

我的问题是我想将货币的本金总额与美元值(value)分开。请查看我数据库中的记录

country_code | Currency_Code  |   Type    |  Principal

=======================================================
| PH         |   PHP          |    PAID   |    100
| PH         |   USD          |    PAID   |    100
=======================================================

Answer 1

试试这个查询:

SELECT `Currency_Code`, SUM(`Principal Amount`) as Total 
FROM `table`
GROUP BY `Currency_Code`