[DataContract]
    public class Employee
    {
        [DataMember]
        public string Name { get; set; }

        [DataMember]
        public Employee Manager { get; set; }
    }

[DataContract]
    public class Department
    {
        [DataMember]
        public string DeptName { get; set; }

        [DataMember]
        public List<Employee> Staff { get; set; }
    }

  [ServiceContract]
    public interface IDepartmentService
    {
        [OperationContract]
        Department GetOneDepartment();
    }

public class DepartmentService : IDepartmentService
    {
        public Department GetOneDepartment()
        {
            List<Employee> listOfEmployees = new List<Employee>();

              var masoud = new Employee() { Name = "Masoud" };
              var saeed = new Employee() { Name = "Saeed", Manager = masoud };
              var peyman = new Employee() { Name = "Peyman", Manager = saeed };
              var mostafa = new Employee() { Name = "Mostafa", Manager = saeed };

              return new Department() { DeptName = "IT", Staff = new List<Employee>() { masoud, saeed, peyman, mostafa } };
        }
    }

 class Program
    {
        static void Main( string[] args )
        {
            DepartmentServiceClient client = new DepartmentServiceClient();

            var result = client.GetOneDepartment();
            WriteDataToFile( result );

            Console.ReadKey();
        }

        private static void WriteDataToFile( Department data )
        {
            DataContractSerializer dcs = new DataContractSerializer( typeof( Department ) );
            var ms = new MemoryStream();
            dcs.WriteObject( ms, data );
            ms.Seek( 0, SeekOrigin.Begin );
            var sr = new StreamReader( ms );
            var xml = sr.ReadToEnd();
            string filePath = @"d:\\data.xml";
            if ( !File.Exists( filePath ) )
            {
                File.Create( filePath );
            }         
                using ( TextWriter writer = new StreamWriter( filePath ) )
                {
                    writer.Write( xml );
                }                      
        }

<Department xmlns="http://schemas.datacontract.org/2004/07/Service" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
  <Name>IT</Name>
  <Staff>
    <Employee>
      <Manager i:nil="true"/>
      <Name>Masoud</Name>
    </Employee>
    <Employee>
      <Manager>
        <Manager i:nil="true"/>
        <Name>Masoud</Name>
      </Manager>
      <Name>Saeed</Name>
    </Employee>
    <Employee>
      <Manager>
        <Manager>
          <Manager i:nil="true"/>
          <Name>Masoud</Name>
        </Manager>
        <Name>Saeed</Name>
      </Manager>
      <Name>Peyman</Name>
    </Employee>
    <Employee>
      <Manager>
        <Manager>
          <Manager i:nil="true"/>
          <Name>Masoud</Name>
        </Manager>
        <Name>Saeed</Name>
      </Manager>
      <Name>Mostafa</Name>
    </Employee>
  </Staff>
</Department>

<Department xmlns="http://schemas.datacontract.org/2004/07/Service" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
  <Name>IT</Name>
  <Staff>
    <Employee z:Id="i1" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
      <Manager i:nil="true"/>
      <Name>Masoud</Name>
    </Employee>
    <Employee z:Id="i2" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
      <Manager z:Ref="i1"/>
      <Name>Saeed</Name>
    </Employee>
    <Employee z:Id="i3" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
      <Manager z:Ref="i2"/>
      <Name>Peyman</Name>
    </Employee>
    <Employee z:Id="i4" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
      <Manager z:Ref="i2"/>
      <Name>Mostafa</Name>
    </Employee>
  </Staff>
</Department>

public interface IDiscountStrategy
{
    decimal ApplyExtraDiscountsTo(decimal originalSalePrice);
}

public class TradeDiscountStrategy : IDiscountStrategy
{
    public decimal ApplyExtraDiscountsTo(decimal originalSalePrice)
    {
        return originalSalePrice * 0.95M;
    }
}

public class NullDiscountStrategy : IDiscountStrategy
{
    public decimal ApplyExtraDiscountsTo(decimal originalSalePrice)
    {
        return originalSalePrice;
    }
}

public class Price
{
    private IDiscountStrategy _discountStrategy = new NullDiscountStrategy();
    private decimal _rrp;
    private decimal _sellingPrice;
    public Price(decimal rrp, decimal sellingPrice)
    {
        _rrp = rrp;
        _sellingPrice = sellingPrice;
    }
    public void SetDiscountStrategyTo(IDiscountStrategy discountStrategy)
    {
        _discountStrategy = discountStrategy;
    }
    public decimal SellingPrice
    {
        get { return _discountStrategy.ApplyExtraDiscountsTo(_sellingPrice); }
    }
    public decimal Rrp
    {
        get { return _rrp; }
    }
    public decimal Discount
    {
        get {
            if (Rrp > SellingPrice)
                return (Rrp - SellingPrice);
            else
                return 0;
        }
    }
    public decimal Savings
    {
        get{
            if (Rrp > SellingPrice)
                return 1 - (SellingPrice / Rrp);
            else
                return 0;
        }
    }
}

public class Product
{
    public int Id {get; set;}
    public string Name { get; set; }
    public Price Price { get; set; }
}

public enum CustomerType
{
    Standard = 0,
    Trade = 1
}

public static class DiscountFactory
{
    public static IDiscountStrategy GetDiscountStrategyFor
        (CustomerType customerType)
    {
        switch (customerType)
        {
            case CustomerType.Trade:
                return new TradeDiscountStrategy();
            default:
                return new NullDiscountStrategy();
        }
    }
}

public interface IProductRepository
{
    IList<Product> FindAll();
}

public static class ProductListExtensionMethods
{
    public static void Apply(this IList<Product> products,
                                        IDiscountStrategy discountStrategy)
    {
        foreach (Product p in products)
        {
            p.Price.SetDiscountStrategyTo(discountStrategy);
        }
    }
}

public class ProductService
{
    private IProductRepository _productRepository;
    public ProductService(IProductRepository productRepository)
    {
        _productRepository = productRepository;
    }
    public IList<Product> GetAllProductsFor(CustomerType customerType)
    {
        IDiscountStrategy discountStrategy =
                                DiscountFactory.GetDiscountStrategyFor(customerType);
        IList<Product> products = _productRepository.FindAll();
        products.Apply(discountStrategy);
        return products;
    }
}

First Name:<br/>
<input type="text" id="txtfname" /><br/>
Last Name:<br/>
<input type="text" id=txtlname /><br/>
Number:<br/>
<input type="tel" id="txttel" /><br/>
<button id="btnsubmit">Save</button><br/>

function GetValues()
{
  let fname=$("#txtfname").val();
  let lname=$("#txtlname").val()
  let tel=$("#txttel").val();
  let row=
  {
    fname:fname,
    lname:lname,
    number:tel
  };
  return row;
}

$("#btnsubmit").click((e)=>{
  e.preventDefault();
  let row=GetValues();

  //save in db
  //get last id
  let statement==db.prepare("select id from numbers order by id desc limit 1");
  let lastRecord=statement.getAsObject({}).id;
  row.id=lastRecord++;
  let count=db.prepare("select count(*) as count from numbers order by id desc").getAsObject({}).count;
  statement.free();
  let insertCommand="insert into numbers values(?,?,?,?)";
  db.run(insertCommand,[row.id,row.fname,row.lname,String(row.number)])
  let newcount=db.prepare("select count(*) as count from numbers order by id desc").getAsObject({}).count;
  SaveChanges();

//show in the table
if(count<newcount)
{
  AddToTable(row);
}
});
});

var statement= db.prepare("SELECT * FROM NUMBERS WHERE fname=@fname AND lname=@lname");

var result = statement .getAsObject({'@fname' :'ali', '@lname' : 'yeganeh'});

statement.bind(['hossein','yeganeh']);

while(statement.step())
{
     var rec=statement.get();
}

  const {ipcRenderer} = require('electron');
function SaveChanges()
{
    ipcRenderer.send("SaveToDb");
}

function AddToTable(row)
{
  let tableBody=$("#people");
  let rowTemplate=`<tr><td>${row.fname}</td><td>${row.lname}</td><td>${row.number}</td><td><button class=
  "btn btn-success btnupdate" data-id="${row.id}" >Edit</button></td></tr>`;
  tableBody.append(rowTemplate);
}

$("#people").on('click','.btnupdate',function(e)
{
  e.preventDefault();

  row.id=$(this).data("id");
  let row=GetValues();
  db.run("UPDATE NUMBERS SET FNAME=?,LNAME=?,NUMBER=? WHERE ID=?",[row.fname,row.lname,row.number,row.id]);
  SaveChanges();
  
  tr=$(this).closest("tr");
  let column=0;
  tr.find("td").each(function(index)
  {
    oldRow=$(this);
    switch(column)
    {
      case 0: //fname
        oldRow.text(row.fname);
        break;
      case 1: //lname
        oldRow.text(row.lname);
        break;
      case 2: //number
        oldRow.text(row.number);
        break;
    }
    column++;
  });
});

db.each("SELECT name,age FROM users WHERE age >= $majority",
  {$majority:18},
  function(row){console.log(row.name)},
                                function(){console.log("done");}
  );

SELECT ID FROM NUMBERS;SELECT FNAME,LNAME FROM NUMBERS

 [
         {columns: ['id'], values:[[1],[2],[3]]},
         {columns: ['fname','lname'], values:[['ali','yeganeh'],['hossein','yeganeh'],['mohammad','yeganeh']]}
    ]

var records=db.exec("select * from numbers");
let values=records[0].values;
let length=values.length;

for(let i=0;i<length;i++)
{
  let object=values[i];
  let row={
    id:object[0],
    fname:object[1],
    lname:object[2],
    number:object[3]
  };
  AddToTable(row);
}

public IList<User> FindUsersContainName(string name, int count = 20)

    public class CityService : ICityService
    {
        private readonly IUnitOfWork _uow;
        private readonly IDbSet<City> _city;

        public CityService(IUnitOfWork uow)
        {
            _uow = uow;
            _city = _uow.Set<City>();
        }

        public int AddCity(City city)
        {
            ...
        }

        public int CitiesCount()
        {
            ...
        }

        public City SearchByCityName(string cityName)
        {
            ....
        }

        public void EditCity(City city)
        {
          ...
        }


        public int RemoveCity(City city)
        {
            ...
        }


        public City GetOneCity(int cityId)
        {
            return _city.Include(a => a.Province).Include(a => a.Province.Country).FirstOrDefault(a => a.CityId == cityId);
        }

        public IList<City> AllCities()
        {
            return _city.Include(a => a.Province).Include(a => a.Province.Country).ToList();
        }

        public IList<City> SearchByProvinceId(int provinceId)
        {
            return _city.Where(c => c.ProvinceId == provinceId).ToList();
        }

        public IList<City> GetCities(int startIndex, int pageSize, string sortexpression)
        {
            if (sortexpression == string.Empty)
            {
                sortexpression = "CityId ASC";
            }

            string sortColumnName = sortexpression.Split(' ')[0];
            string sortDirection = sortexpression.Split(' ')[1];
            var citiesQuery = _city.Include(a => a.Province).Include(a => a.Province.Country).AsQueryable();
            switch (sortColumnName)
            {
                case "CityId":
                    citiesQuery = ((sortDirection.ToLower() == "asc") ? citiesQuery.OrderBy(a => a.CityId) : citiesQuery.OrderByDescending(a => a.CityId));
                    break;
                case "CityName":
                    citiesQuery = ((sortDirection.ToLower() == "asc") ? citiesQuery.OrderBy(a => a.CityName) : citiesQuery.OrderByDescending(a => a.CityName));
                    break;
                case "TelCode":
                    citiesQuery = ((sortDirection.ToLower() == "asc") ? citiesQuery.OrderBy(a => a.TelCode) : citiesQuery.OrderByDescending(a => a.TelCode));
                    break;
...
            }
            return citiesQuery.Skip(startIndex).Take(pageSize).ToList();
        }

....و هر متد دیگری که نیاز دارید
    }