title: EFCore.BulkExtensions - BulkUpdate using pimarykey
body: <p>We are trying to BulkUpdate(<a href="https://github.com/borisdj/EFCore.BulkExtensions" rel="nofollow noreferrer">EFCore.BulkExtensions</a>) a table based on primary key. We need to update ONLY <code>Name</code> based on <code>Id</code> and not <code>Age</code></p>
  
  <p>Model </p>
  
  <pre><code>public class Student 
  {
      public int Id { get; set; } // Primary Key
      public string Name { get; set; }
      public int Age { get; set; }
  }
  </code></pre>
  
  <p>Here is the code I used to try to update a student's name using primary key Id</p>
  
  <pre><code>List&lt;Student&gt; students = new List&lt;Student&gt;();
  students.Add(new Student()
  {
      Id = 1,
      Name = "Name 1",
      Age = 25
  });
  
  var updateByProperties = new List&lt;string&gt; { nameof(Student.Id) };
  var propToExclude = new List&lt;string&gt; { nameof(Student.Id) };
  var bulkConfig = new BulkConfig { UpdateByProperties = updateByProperties, PropertiesToExclude = propToExclude };
  _dbContext().BulkUpdate(students, bulkConfig);
  </code></pre>
  
  <p>My expectation here is it will update column <code>Name</code> of a row which has <code>Id</code> as 1 but I am getting the following error </p>
  
  <pre><code>The given key 'Id' was not present in the dictionary.
  </code></pre>
  
  <p>So how do I BulkUpdate(EFCore.BulkExtensions) a table based on primary key.</p>