title: .NET 4.0 substitutes for .NET 4.5 namespaces
body: <p>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.</p>
  
  <p>There are a few functions in the code which use dll files which are available only for .NET 4.5, for example <code>System.ComponentModel.DataAnnotations.Schema</code>.</p>
  
  <p>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?</p>
  
  <p>This is my current code using .NET 4.5: </p>
  
  <pre><code> [Table("UserProfile")]
      public class UserProfile
      {
          [Key]
          [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
          public int UserId { get; set; }
          public string UserName { get; set; }
      }
  </code></pre>
  
  <p>As you can see <code>DatabaseGeneratedAttribute</code> is available under the <code>System.ComponentModel.DataAnnotations.Schema</code> namespace, which is a part of .NET 4.5.</p>
  
  <p>Any suggestions on what the corresponding functions/attributes that could be used in .NET 4 to represent the same logic?</p>
  
  <p><strong>Note:</strong> In the code snippet given above, I get errors on <code>Table</code> and <code>DatabaseGeneratedAttribute</code> as </p>
  
  <blockquote>
    <p>The type or namespace name 'Table' could not be found (are you missing a using directive or an assembly reference?)</p>
  </blockquote>
  
  <p>and </p>
  
  <blockquote>
    <p>The type or namespace name 'DatabaseGeneratedAttributeAttribute' could not be found (are you missing a using directive or an assembly reference?)</p>
  </blockquote>
  
  <p>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.</p>