Question

I just set about updating a project from Entity Framework 4.3.1 and .NET 4 to Entity Framework 5.0 and .NET 4.5. I updated the .NET version first, and ensured that I’m referencing EF 5.0.0.0 rather than the .NET 4 compatible 4.4.0.0.

I have a class structure like

public class MyBase
{
    [NotMapped]
    public bool MyProperty { get; set; }
}

public class MyDefinition : MyBase
{
    // Some other properties
}

When I attempt to load some MyDefinition instances

using (MyContext ctx = new MyContext())
{
    ctx.Configuration.AutoDetectChangesEnabled = false;
    ctx.Configuration.LazyLoadingEnabled = false;
    ctx.Configuration.ProxyCreationEnabled = false;

    var defs = from def in ctx.MyDefinitions.AsNoTracking() select def;

    foreach (MyDefinition def in defs) // <-- Exception here
    {
        // Do stuff
    }
}

I get a SqlException

Invalid column name ‘MyProperty’.

It is as if NotMapped is respected for purposes of determining whether the existing schema is valid, but the SELECT generated by EF 5 expects there to be a MyProperty column.

The base class and derived class are defined in different assemblies. Both assemblies were carefully checked to ensure they reference EF 5.0.0.0 and target .NET 4.5.

Intellisense claims that NotMapped is System.ComponentModel.DataAnnotations.Schema.NotMapped

How can I prevent EF 5 from selecting that non-existent column?

Answer 1

D’oh!

I also updated to VS 2012 today. Something unrelated broke with a post-build event, which caused an earlier version of the assembly containing the base class to be available to the derived class. Fixing the post build event resolved the issue.