如何对 SQL 查询中的两个字段求和 [英] How to SUM two fields within an SQL query

问题描述

我需要获取同一行内两个字段的总和，然后在同一行末尾的字段中输入该数字.

I need to get the total of two fields which are within the same row and input that number in a field at the end of that same row.

这是我的代码.

Sum(tbl1.fld1 + tbl1.fld2) AS [Total]

这是 SUM 函数的用途，还是只能使用 SUM 函数来获取列的总数?

Is this what the SUM function is used for, or can you only use the SUM function for getting the total of a column?

谢谢

推荐答案

SUM 是一个聚合函数.它将计算每个组的总数.+ 用于计算一行中的两列或更多列.

SUM is an aggregate function. It will calculate the total for each group. + is used for calculating two or more columns in a row.

考虑这个例子，

ID  VALUE1  VALUE2
===================
1   1       2
1   2       2
2   3       4
2   4       5

 

SELECT  ID, SUM(VALUE1), SUM(VALUE2)
FROM    tableName
GROUP   BY ID

结果

ID, SUM(VALUE1), SUM(VALUE2)
1   3           4
2   7           9

 

SELECT  ID, VALUE1 + VALUE2
FROM    TableName

结果

ID, VALUE1 + VALUE2
1   3
1   4
2   7
2   9

 

SELECT  ID, SUM(VALUE1 + VALUE2)
FROM    tableName
GROUP   BY ID

结果

ID, SUM(VALUE1 + VALUE2)
1   7
2   16

这篇关于如何对 SQL 查询中的两个字段求和的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！