DbArithmeticExpression参数必须具有数字通用类型 [英] DbArithmeticExpression arguments must have a numeric common type

问题描述

TimeSpan time24 = new TimeSpan(24, 0, 0);
TimeSpan time18 = new TimeSpan(18, 0, 0);    

// first get today's sleeping hours
List<Model.Sleep> sleeps = context.Sleeps.Where(
    o => (clientDateTime - o.ClientDateTimeStamp < time24) && 
          o.ClientDateTimeStamp.TimeOfDay > time18 && 
          clientDateTime.TimeOfDay < time18 && 
          o.UserID == userid).ToList(); 

此Linq表达式抛出此异常：

This Linq expression throws this exception:

DbArithmeticExpression arguments must have a numeric common type.

请帮助！

推荐答案

实体框架不支持使用 DateTime 的算术。您必须使用 DbFunctions *。所以，对于你的陈述的第一部分，例如：

Arithmetic with DateTime is not supported in Entity Framework. You have to use DbFunctions*. So, for the first part of your statement, something like:

var sleeps = context.Sleeps(o =>
    DbFunctions.DiffHours(o.ClientDateTimeStamp, clientDateTime) < 24);

请注意， DiffHours 方法接受 Nullable< DateTime> 。

_{* EntityFunctions 。}

这篇关于DbArithmeticExpression参数必须具有数字通用类型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！