Bug #67443 Exception on EF Select with enum and bytes
Submitted: 1 Nov 2012 7:04 Modified: 7 Dec 2012 20:11
Reporter: Andrey Veselov Email Updates:
Status: No Feedback Impact on me:
Category:Connector / NET Severity:S1 (Critical)
Version:6.5.4/6.6.4 OS:Microsoft Windows
Assigned to: Assigned Account CPU Architecture:Any
Tags: EF, enum, SELECT

[1 Nov 2012 7:04] Andrey Veselov
Following code throws exception

The specified cast from a materialized 'System.Byte' type to the 'EnumTest.TestEnum' type is not valid.

if Enum is not Int32. Code uses EF5 under .NET 4.5. Compiled under VS2012. I try 6.5.4 and 6.6.4-RC1 - both failed.

How to repeat:
// Full source code without EDMX file. Use any with your database
namespace EnumTest
    using System.Collections;
    using System.Collections.Generic;
    using System.Linq;

    public enum TestEnum : byte
        Value0 = 0,
        Value1 = 1,
        Value2 = 2

    public class TestClass
        public string Name { get; set; }
        public TestEnum Value { get; set; }

    class Program
        static void Main(string[] args)
            IEnumerable<TestClass> list;

            using (var ctx = new tennisbetsite_oncourtEntities()) {
                var c = ctx.rounds.Select(a => new TestClass {
                    Name = a.Name,
                    Value = TestEnum.Value2

                list = c.ToList(); // Exception

And if you replace
Value = TestEnum.Value2
ValueAsByte = (byte)TestEnum.Value2
it will throw: "Exception has been thrown by the target of an invocation."

But with:

public enum TestEnum // removed ": byte"
    Value0 = 0,
    Value1 = 1,
    Value2 = 2

all works fine.

Suggested fix:
Not found. Even workaround with additional property (byte) and byte value fails with exception.
[1 Nov 2012 7:06] Andrey Veselov
BTW same code works with MSSQL so there is not a .NET/EF bug.
[7 Nov 2012 20:11] Gabriela Martinez Sanchez
Hi Andrey,

Currently our support for EF 5 and .net framework 4.5 is a work in progress (Core Entity Framework API in the .NET Framework 4 doesn't support enums). So this functionality would be completed in our next released version. If you want to know about the progress on this you can take a look on the forums where we keep posting on any news about Connector/Net (http://forums.mysql.com/list.php?38) or at our official blog (https://blogs.oracle.com/MySqlOnWindows/).

Please let us know if you have any question on this.
[8 Dec 2012 1:00] Bugs System
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".