ADO Net C# Tutorial

using System;
using System.Data;
using System.Data.SqlClient;
    class PersistAdds
    {
        static void Main(string[] args)
        {
            string connString = @"server = .\sqlexpress;integrated security = true;database = northwind";
            string qry = @"select * from employees where country = 'UK'";
            string ins = @"insert into employees(firstname,lastname,titleofcourtesy,city,country)values(@firstname,@lastname,@titleofcourtesy,@city,@country)";
            SqlConnection conn = new SqlConnection(connString);
            try
            {
                SqlDataAdapter da = new SqlDataAdapter();
                da.SelectCommand = new SqlCommand(qry, conn);
                DataSet ds = new DataSet();
                da.Fill(ds, "employees");
                DataTable dt = ds.Tables["employees"];
                DataRow newRow = dt.NewRow();
                newRow["firstname"] = "Roy";
                newRow["lastname"] = "Beatty";
                newRow["titleofcourtesy"] = "Sir";
                newRow["city"] = "Birmingham";
                newRow["country"] = "UK";
                dt.Rows.Add(newRow);
                foreach (DataRow row in dt.Rows)
                {
                    Console.WriteLine(row["firstname"]);
                    Console.WriteLine(row["lastname"]);
                    Console.WriteLine(row["city"]);
                }
                SqlCommand cmd = new SqlCommand(ins, conn);
                cmd.Parameters.Add("@firstname",SqlDbType.NVarChar,10,"firstname");
                cmd.Parameters.Add("@lastname",SqlDbType.NVarChar,20,"lastname");
                cmd.Parameters.Add("@titleofcourtesy",SqlDbType.NVarChar,25,"titleofcourtesy");
                cmd.Parameters.Add("@city",SqlDbType.NVarChar,15,"city");
                cmd.Parameters.Add("@country",SqlDbType.NVarChar,15,"country");
                da.InsertCommand = cmd;
                da.Update(ds, "employees");
            }
            catch (Exception e)
            {
                Console.WriteLine("Error: " + e);
            }
            finally
            {
                conn.Close();
            }
        }
    }