title: C# and EF cannot insert NULL to Id column
body: <p>I have entity in C# that has Id column. This is Primary key. But I don't to have it as Identity column. I want to assign value to Id column in my code in C#.
  Entity:</p>
  
  <pre><code>    public class MasterReview
          {
              public int Id { get; set; }
  </code></pre>
  
  <p>In database I have column Id, Identity Specification is set as no.
  In C# when I add new entity I set value to Id:</p>
  
  <pre><code>    public void Add(int reviewId, string title, string language, string assignee)
              {
                  using (var uow = unitOfWorkFactory.CreateUnitOfWork())
                  {
                      uow.MasterReviewRepository.Add(new Models.MasterReview()
                      {
                          Id = reviewId,
                          Title = title,
                          Language = language,
                          Assignee = assignee
                      });
  
                      uow.Save();
                  }
              }
  </code></pre>
  
  <p>And when I call <code>uow.Save</code> I get error: </p>
  
  <blockquote>
    <p>Cannot insert the value NULL into column 'Id', table 'MyApp.dbo.MasterReview'; column does not allow nulls. INSERT fails.</p>
  </blockquote>
  
  <p>Value is set, is not empty. It's 3.</p>
  
  <p><a href="https://i.stack.imgur.com/XxeRM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XxeRM.png" alt="enter image description here"></a></p>