Question
I'm trying to select a list of integers and it's raising an exception.
Exception message: System.ArgumentException: Expression of type 'System.Collections.Generic.IAsyncEnumerable1[System.Int32]' cannot be used for parameter of type 'System.Collections.Generic.IAsyncEnumerable1[System.Object]' of method 'System.Collections.Generic.IAsyncEnumerable1[MyProject.Model.Entities.MyTable] CastModel' Parameter name: arg0
Steps to reproduce
Model
public class MyTable {
public int MyTableId { get; set; }
public int SomeKey { get; set; }
public int MyFieldIntegerIWant { get; set; }
}
Run the query below (or one like it):
int keyId;
var ids = await context.MyTable.AsNoTracking()
.Where(x => x.SomeKey.Equals(keyId))
.Select(x => x.MyFieldIntegerIWant)
.ToListAsync();
Further technical details
EF Core version: 1.1.0
Database Provider: Microsoft.EntityFrameworkCore.SqlServer
Operating system: Windows 7
IDE: Visual Studio 2015
UPDATE:
The issue had something to do with EF Plus' QueryFilters
https://github.com/zzzprojects/EntityFramework-Plus/issues/133
Expert Answer
After discussion with @thejason,
The issue was not caused by Entity Framework Plus but how EF Core handle cast.
The issue can be easily reproduced using the following code:
using (var ctx = new CurrentContext())
{
int keyId = 1;
var ids = ctx.MyTables
.Cast<IMyTable>()
.Cast<MyTable>()
.Where(x => x.SomeKey.Equals(keyId))
.Select(x => x.MyFieldIntegerIWant)
.ToList();
}
Cast method will be fixed in EF Core 2.x
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