SQL SUM 问题 [英] SQL SUM question

问题描述

我有一个关于 sql 中的 SUM 的问题，

Hi I have a question about SUM in sql,

我有一个类似这样的查询

I have a query that looks like this

SELECT 
 SUM ( table_one.field + table_two.field )  as total_field
 SUM ( total_field + table_one.anotherfield )
FROM 
 table_one
JOIN
 table_two ON table_one.id = table_two.id
WHERE 
 table_one = 1

但这不起作用(不要介意 JOIN 语句中可能的输入错误，只有第二个 SUM 是查询在没有该 SUM 的情况下完美运行的可能性)

But this doesn't work ( dont mind possible typing errors in JOIN statement, only the second SUM is the probly the query works perfecly without that SUM)

还有其他方法可以做到这一点，因为我需要在我的应用程序中使用 total_field.我当然可以在应用程序中添加这些数字，但我更喜欢在 sql 中添加.

Is there another way to do it, as I need the total_field within my application. I can ofcource add those numbers within the application but I prefer to do it in sql.

推荐答案

不能在聚合中使用列别名来引用值，只需再次 SUM；

You cannot use the column alias in an aggregate to reference the value, just SUM again;

SELECT 
 SUM ( table_one.field + table_two.field ) as total_field, --your missing a , also
 SUM ( table_one.field + table_two.field + table_one.anotherfield )
FROM 
 table_one
JOIN
 table_two ON table_one.id = table_two.id
WHERE 
 table_one = 1

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