title: Exclude properties for migrations
body: <p>I have <em>properties</em> on my model that I don't want to generate fields in the <strong>tables</strong> after a migration.</p>
  
  <p>Is it possible to exclude <em>properties</em> for Entity Framework Core migrations?</p>
  
  <p>Is there an attribute for the model or some Fluent API method on my <code>DbContext</code> for this?</p>