SUM 在 SQL Server 中的总时间 [英] SUM total time in SQL Server

问题描述

我对 SQL Server 中的 SUM 运算符有问题.当我编写此查询时:

I have a problem with the SUM operator in SQL Server. When I write this query:

SELECT StudentID, StudentName, SUM(time) as 'TotalTime' 
FROM WorkNote
GROUP BY StudentID, StudentName

我收到此错误:

求和运算符的操作数数据类型时间无效.

Operand data type time is invalid for sum operator.

SUM 是否有其他方法或从记录中计算总时间?

Is there some other method for SUM or to calculate the total times from the records?

在我的WorkNote表中，time列的类型是Time(7)，我想SUM代码>每个学生的所有(总)次.

In my WorkNote table, the type of column time is Time(7), and I want to SUM all (total) times for every student.

推荐答案

如果时间在 hh/mm/ss then ::

if the time in hh/mm/ss then ::

SELECT studentid,studentname,
         DATEADD(ms, SUM(DATEDIFF(ms, '00:00:00.000', mytime)), '00:00:00.000') as time
    FROM
         worknote

这篇关于SUM 在 SQL Server 中的总时间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！