List< String> list =  new  List< String>（）{  A ，  B，  C}; 
使用（ var  con =  new  SqlConnection（connectionString））
 {
 con.Open（）; 
使用（ var  cmd =  new  SqlCommand（  INSERT INTO TABLE（Column）VALUES（@Column），con））
 {
 cmd.Parameters.Add（  @ Column，SqlDbType.VarChar ）; 
 foreach （ var   value  在列表中）
 {
 cmd.Parameters [  @ Column]。值=  value ; 
 int  rowsAffected = cmd.ExecuteNonQuery（）; 
} 
} 
} 

in CustomerDto i have written these code

public CustomerDTO()
        {}

        public string Name
        {
            get;
            set;
        }
        public string Gender
        {
            get;
            set;
        }
        public string Age
        {
            get;
            set;
        }
    }

in button click event

List<CustomerDTO> GetCustomerInfo = new List<CustomerDTO>();
            GetCustomerInfo = GetCustomerDetail(2);
 CustomerOrder customerOrder = new CustomerOrder();
            customerOrder.From = "";
            customerOrder.To = "";
SaveCustomerDetails(GetCustomerInfo, txtEmail.Text, txtMobile.Text, customerOrder);
        }

in GetcustomerDetails() method i written like this

private List<CustomerDTO> GetCustomerDetail(int SeatCount)
        {
            List<CustomerDTO> GetCustomers = new List<CustomerDTO>();
            for (int i = 1; i <= SeatCount; i++)
            {
                CustomerDTO EachCustomerDTO = new CustomerDTO();
                if (i == 1)
                {
                    EachCustomerDTO.Name = txtName1.Text;
                    if (rblGender1.SelectedIndex == 0)
                        EachCustomerDTO.Gender = "Male";
                    else
                        EachCustomerDTO.Gender = "FeMale";
                    EachCustomerDTO.Age = txtAge1.Text;
                }
                else if (i == 2)
                {
                    EachCustomerDTO.Name = txtName2.Text;
                    if (rblGender2.SelectedIndex == 0)
                        EachCustomerDTO.Gender = "Male";
                    else
                        EachCustomerDTO.Gender = "FeMale";
                    EachCustomerDTO.Age = txtAge2.Text;
                }
                else if (i == 3)
                {
                    EachCustomerDTO.Name = txtName3.Text;
                    if (rblGender3.SelectedIndex == 0)
                        EachCustomerDTO.Gender = "Male";
                    else
                        EachCustomerDTO.Gender = "FeMale";
                    EachCustomerDTO.Age = txtAge3.Text;
                }
                else if (i == 4)
                {
                    EachCustomerDTO.Name = txtName4.Text;
                    if (rblGender4.SelectedIndex == 0)
                        EachCustomerDTO.Gender = "Male";
                    else
                        EachCustomerDTO.Gender = "FeMale";
                    EachCustomerDTO.Age = txtAge4.Text;
                }
                else if (i == 5)
                {
                    EachCustomerDTO.Name = txtName5.Text;
                    if (rblGender5.SelectedIndex == 0)
                        EachCustomerDTO.Gender = "Male";
                    else
                        EachCustomerDTO.Gender = "FeMale";
                    EachCustomerDTO.Age = txtAge5.Text;
                }
                else if (i == 6)
                {
                    EachCustomerDTO.Name = txtName6.Text;
                    if (rblGender6.SelectedIndex == 0)
                        EachCustomerDTO.Gender = "Male";
                    else
                        EachCustomerDTO.Gender = "FeMale";
                    EachCustomerDTO.Age = txtAge6.Text;
                }
                GetCustomers.Add(EachCustomerDTO);
            }
            return GetCustomers;
        }  

in SaveCustomerDetails method i written like this

private void SaveCustomerDetails(List<CustomerDTO> CoustomerDetails, string EmailId, string Mobile, CustomerOrder CustomerOrderDetail)
       {
           try
           {


               string connStr = System.Configuration.ConfigurationManager.ConnectionStrings["myConnectionString"].ConnectionString;
               SqlConnection con = new SqlConnection(connStr);
               con.Open();
               SqlCommand cmd = new SqlCommand();
               cmd.Connection = con;
               cmd.CommandType = CommandType.StoredProcedure;
               cmd.CommandText = "SaveCustomerRegistration";
               cmd.Parameters.Add("@Email", EmailId);
               cmd.Parameters.Add("@Mobile", Mobile);
               object objTab =  cmd.ExecuteScalar();
               for (int i = 0; i < ; i++)
               {

               }


               con.Close();
           }
           catch (Exception ex)
           {

           }
           finally
           {

           }

can u suggest me how can i write the code for saving the database

thanks in advance

List<String> list = new List<String>() { "A", "B", "C" };
using (var con = new SqlConnection(connectionString))
{
    con.Open();
    using (var cmd = new SqlCommand("INSERT INTO TABLE(Column)VALUES(@Column)", con))
    {
        cmd.Parameters.Add("@Column", SqlDbType.VarChar);
        foreach (var value in list)
        {
            cmd.Parameters["@Column"].Value = value;
            int rowsAffected = cmd.ExecuteNonQuery();
        }
    }
}