MySql 合计计算

Question

我使用公式 C=A/B*1000000 创建了用于计算 "C" 的工作语句。

这按预期工作并且 C 列计算正确：

Select chemicals.Region As Region,
chemicals.Totalt As `A`,
`area`.`m2` As `B`,
((chemicals.Totalt / `area`.`m2`) * 1000000) As C
From (chemicals Join `area` On chemicals.branch = `area`.branch)

现在我需要在汇总报告中使用相同的公式，所以我尝试了这个：

Select chemicals.Region As Region,
sum(chemicals.Totalt) As `A`,
sum(`area`.`m2`) As `B`,
sum( ((chemicals.Totalt / `area`.`m2`) * 1000000)) As C
From (chemicals Join `area` On chemicals.branch = `area`.branch) GROUP BY Region

但是 "C" 的值计算不正确。

我相信有办法解决这个问题，但是简单地在 "C" 计算中添加求和函数是不正确的。（顺便说一下，A 列和 B 列是正确的）。

感谢大家的帮助！

Answer 1

如评论中所述，以下解决方案将起作用：

((sum(chemicals.TotalT) / sum(area.m2)) * 1000000) as C

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