public class Blog
{
  public int BlogId { get; set; }
  public string Url { get; set; }

  public List<Post> Posts { get; set; }
}

public class Post
{
  public int PostId { get; set; }
  public string Title { get; set; }
  public string Content { get; set; }

  public int BlogId { get; set; }
  public Blog Blog { get; set; }
}

    public class BloggingContext : DbContext
    {
        public BloggingContext()
        { }

        public BloggingContext(DbContextOptions options)
            : base(options)
        { }

        public DbSet<Blog> Blogs { get; set; }
        public DbSet<Post> Posts { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                optionsBuilder.UseSqlServer(@"Server=(localdb)\mssqllocaldb;Database=Demo.Includes;Trusted_Connection=True;");
                optionsBuilder.ConfigureWarnings(warnings => warnings.Log(CoreEventId.IncludeIgnoredWarning));
                optionsBuilder.UseLoggerFactory(new LoggerFactory().AddConsole((message, logLevel) =>
                {
                    return true;
                    /*return logLevel == LogLevel.Debug &&
                           message.StartsWith("Microsoft.EntityFrameworkCore.Database.Command");*/
                }));
            }
        }
    }

var blogs = context.Blogs
    .Include(blog => blog.Posts)
    .Select(blog => new
    {
       Id = blog.BlogId,
       Url = blog.Url
    })
    .ToList();

 warn: Microsoft.EntityFrameworkCore.Query[100106]
The Include operation for navigation '[blog].Posts' is unnecessary and was ignored because the navigation is not reachable in the final query results. See https://go.microsoft.com/fwlink/?linkid=850303 for more information.

SELECT [blog].[BlogId] AS [Id], [blog].[Url]
FROM [Blogs] AS [blog]

 optionsBuilder.ConfigureWarnings(warnings => warnings.Throw(CoreEventId.IncludeIgnoredWarning));