Question

我有一个充满交易的数据库表。交易包含人们返回项目的负数。我想将所有金额字段相加，同时从总计中减去返回的负值。我怎么能这样做并输出呢？目前我能做的最好的就是：

  SELECT SUM(amount) 
  FROM outputaddition 
  GROUP by SIGN(amount);

但这只会在同一栏中放置正面和负面。

Answer 1

SELECT personId,SUM(CASE WHEN amount<0 THEN amount ELSE 0 END) as NegativeTotal,
       SUM(CASE WHEN amount>=0 THEN amount ELSE 0 END) as PostiveTotal
FROM outputaddition
GROUP BY personID

如果您想要单列

SELECT personId,SUM(amount) as Total
FROM outputaddition
GROUP BY personID

Answer 2

我担心你的答案含糊不清;我们不确定你在问什么。

最简单的说，如果“减去负值”意味着你只想忽略负面回报：

选择总和（金额）其中数量> 0;

Answer 3

试试这个，

SELECT SUM(amount)  as ActualTotal
    ,Sum(Case When amount > 0 then amount else 0 end) totalOfPositiveOnly
  FROM outputaddition

MySQL总和正面和负面 - 计算货币交易的确切总数

3 个答案: