title: System.Data.Entity.Infrastructure.DbUpdateException error even when i am not updating the id column
body: <p>I am working on a project where I am using Entity framework to manipulate a DB on sql server 2014.
  My code is the following:</p>
  
  <pre><code>private void BtnAddUser(object sender, EventArgs e)
      {
          var u = new User();
          u.username = txtBoxNewUser.Text;
          u.password = txtBoxNewPass.Text;
          u.rank = cmbBoxRank.GetItemText(this.cmbBoxRank.SelectedItem);
          using (var db = new ProjetPooEntities2())
          {
              db.Users.Add(u);
              db.SaveChanges();
          }
  
      }
  </code></pre>
  
  <p>Please note that the code runs perfectly but it when i press the Add button to add the created user to the db an error shows on "db.saveChanges()" and it says:</p>
  
  <blockquote>
    <p>System.Data.Entity.Infrastructure.DbUpdateException: 'An error occurred while updating the entries. See the inner exception for details.'
    And the inner exception is:
    SqlException: Cannot insert explicit value for identity column in table 'User' when IDENTITY_INSERT is set to OFF.</p>
  </blockquote>
  
  <p>I have set the identity column in the db to "id" and it is set to auto-increment by 1 starting from 1.
  I have tried searching a lot for a solution but i found nothing.
  Any help will be appreciated!!</p>