using System; using System.Data; using System.Data.SqlClient; class ModifyDataTable { static void Main(string[] args) { string connString = @"server = .\sqlexpress;integrated security = true;database = northwind"; string sql = @"select * from employees where country = 'UK'"; SqlConnection conn = new SqlConnection(connString); try { SqlDataAdapter da = new SqlDataAdapter(); da.SelectCommand = new SqlCommand(sql, conn); DataSet ds = new DataSet(); da.Fill(ds, "employees"); DataTable dt = ds.Tables["employees"]; dt.Columns["firstname"].AllowDBNull = true; dt.Rows[0]["city"] = "Wilmington"; 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"]); } } catch (Exception e) { Console.WriteLine("Error: " + e); } finally { conn.Close(); } } }