Question

Have problem with linq expressions.
I want to get from db some data ordered by datetime. Early there was sorting by string field.
Sorting expression (by string):

Expression<Func<Matter, Object>> result = e => e.MatterNumber;
//In debug mode: {e => e.MatterNumber}

Works fine

Sorting expression (by datetime or int):

Expression<Func<Matter, Object>> result = e => e.Created;
//In debug mode: {{e => Convert(e.Created)}}

This rise an error: {“Unable to cast the type ‘System.Int32’ to type ‘System.Object’. LINQ to Entities only supports casting Entity Data Model primitive types.”}

Please help 🙂

Answer 1

alexei, you might wanna take a look at this SO Question:

Entity Framework: LINQ to Entities only supports casting Entity Data Model primitive types

or this one here:

Help me understand "LINQ to Entities only supports casting Entity Data Model primitive types"

and finally on SO:

Entityframework 4.0 .CreateQuery<T> and OrderBy exception

and on the forums.asp.net:

http://forums.asp.net/t/1580414.aspx/1

all 4 deal with this issue in slightly differing ways but hopefully will be helpful in your scenario.