DbArithmeticExpression arguments must have a numeric common type

Question

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

// first get today\'s sleeping hours
List sleeps = contex         


        

Answer 1

Arithmetic with DateTime is not supported in Entity Framework 6 and earlier. 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);

Note that the DiffHours method accepts Nullable.

Entity Framwork core (when used with Sql Server, maybe other db providers) supports the DateTime AddXxx functions (like AddHours). They're translated into DATEADD in SQL.

_{*EntityFunctions prior to Entity Framework version 6.}