Try like this,,
modify as per your needs, this will help you...
using System.Collections.Generic;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
List<Entity> list = new List<Entity>();
list.Add(new Entity() { ID = 1, Name = "karthik", Address = "Bangalore" });
list.Add(new Entity() { ID = 1, Name = "Parthip", Address = "Ahmdabad" });
list.Add(new Entity() { ID = 1, Name = "Krishna", Address = "Delhi" });
string conn = @"Data Source=.;Initial Catalog=databasename;Integrated Security=True;";
foreach (Entity item in list)
{
SqlCommand sqlCmd = new SqlCommand();
SqlConnection objConn = new SqlConnection();
objConn.ConnectionString = conn;
objConn.Open();
sqlCmd.Connection = objConn;
sqlCmd.CommandTimeout = 30;
string values = string.Format("({0},'{1}','{2}')", item.ID, item.Name, item.Address);
sqlCmd.CommandText = "insert into tablename (ID,Name,Address,Column1,Column2....) values " + values;
sqlCmd.ExecuteNonQuery();
}
}
class Entity
{
public int ID { get; set; }
public string Name { get; set; }
public string Address { get; set; }
}
}