using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
 
namespace ForgetCode
{   
    public class MainClass
    {
        public static void Main()
        {
            // Load your DB file here
            var customerQuery =
            from cust in customers
            where cust.City == "London"
            select cust;
 
            foreach (var customer in customerQuery)
            {
                Console.WriteLine(customer.LastName + ", " + customer.FirstName);
            }
        }
    }
}