.NET 4.0 substitutes for .NET 4.5 namespaces

Question

There is some code for an MVC application which was built using .NET 4.5 as a framework in VS 2012. My current system forces me to work on VS 2010. I managed to open the VS2012 solution in my VS2010, but the thing is that VS2010 supports only up to .NET 4.

There are a few functions in the code which use dll files which are available only for .NET 4.5, for example System.ComponentModel.DataAnnotations.Schema.

So, are there any substitute functions/attributes which are available in .NET 4, which I could use to do the same that is being done on .NET 4.5 right now?

This is my current code using .NET 4.5:

 [Table("UserProfile")]
    public class UserProfile
    {
        [Key]
        [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
        public int UserId { get; set; }
        public string UserName { get; set; }
    }

As you can see DatabaseGeneratedAttribute is available under the System.ComponentModel.DataAnnotations.Schema namespace, which is a part of .NET 4.5.

Any suggestions on what the corresponding functions/attributes that could be used in .NET 4 to represent the same logic?

Note: In the code snippet given above, I get errors on Table and DatabaseGeneratedAttribute as

The type or namespace name 'Table' could not be found (are you missing a using directive or an assembly reference?)

and

The type or namespace name 'DatabaseGeneratedAttributeAttribute' could not be found (are you missing a using directive or an assembly reference?)

respectively. So, I am guessing that I just need to find the corresponding classes in NET 4.0 and things would fall into place. Your help is deeply appreciated.

Answer 1

I saw the same issue after changing from .NET 4.5 to 4.0. According to this article "there is a special version of the Entity Framework assembly" for .NET 4.0 containing DataAnnotations, which have otherwise been incorporated into .NET 4.5.

Reinstalling Entity Framework made System.ComponentModel.DataAnnotations.Schema work again. Reinstall by typing the following in Package Manager Console:

Uninstall-Package EntityFramework
Install-Package EntityFramework