title: The property 'PropertyName' could not be mapped, because it is of type 'List<decimal>'
body: <p>I got this problem when I try to create the database with EntityFramework Core:</p>
  
  <blockquote>
    <p>The property 'Rating.RatingScores' could not be mapped, because it is of type 'List' which is not a supported primitive type or a valid entity type. Either explicitly map this property, or ignore it using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.</p>
  </blockquote>
  
  <p>Here is the class:</p>
  
  <pre><code>public class Rating
  {
      public int Id { get; set; }
  
      public List&lt;decimal&gt; RatingScores { get; set; }
  
      public decimal Score
      {
          set =&gt; Score = value;
          get =&gt; Math.Round(RatingScores.Sum() / RatingScores.Count, 1);
      }
  }
  </code></pre>