title: EF Core Bulk Update (Update Range) Increment an existing column value
body: <p>I have a List of an Entity for e.g List of Customer entity.</p>
  
  <p>I am using a Bulk update as context.Customer.UpdateRange(Customer);</p>
  
  <p>My requirement is I need to increment an Existing Column value with a new value. for e.g Inside Customer table Qty column needs to be updated as 
  Qty = Qty + current_Value.</p>
  
  <p>I can do this by looping through the Customer List and update the column one by one customer object. But I wish to do this while bulk update (UpdateRange)</p>
  
  <p>The technology I am using - ASP.NET Core, MVC Core, EF Core</p>