Beginners' guide to using MongoDB 4.0.2 and the official C# driver

using System;
using System.Linq;

namespace TestMongo
{
    using System.Text.RegularExpressions;

    using MongoDB.Driver;
    using MongoDB.Driver.Linq;

    public partial class Program
    {
       public static void DemoLinq(MongoCollection<ClubMember> collection)
       {
           var names =
              collection.AsQueryable().Where(p => p.Lastname.StartsWith("R") && p.Forename.EndsWith("an")).OrderBy(
                  p => p.Lastname).ThenBy(p => p.Forename).Select(p => new { p.Forename, p.Lastname });

           Console.WriteLine("People whos Lastname starts with 'R' and Forename ends with 'an'");
           foreach (var name in names)
           {
               Console.WriteLine(name.Lastname + " " + name.Forename);
           }

           var regex = new Regex("ar");
           Console.WriteLine("List of Lastnames containing the substring 'ar'");
           IQueryable<string> regexquery =
               collection.AsQueryable().Where(py => regex.IsMatch(py.Lastname)).Select(p => p.Lastname).Distinct();

           foreach (string name in regexquery)
           {
               Console.WriteLine(name);
           }



       }

    }

}