Import Web API data into SQL Server database

I am new to Web API and I have a questions: how to import Web API data into a SQL Server database.

My Web API is created with data reader and I have searched in the internet, it seems like it could be import data with data reader. I want to test importing data with Web API, so I can know is my Web API working or not.

Code:

[HttpGet]
public IHttpActionResult GetAll()
{
    List<webapi> web = new List<webapi>();

    using (SqlCommand cmd = new SqlCommand("SELECT U.UserID, U.Name, U.Mobile, U.Age, U.Birthday, A.Address, A.Country From tbluser U inner join tblAddress A where A.Country=U.Country", connection))
    {
        SqlDataReader sdr = cmd.ExecuteReader();

        while (sdr.Read())
        {
            web.Add(new webapi()
                    {
                        UserId = Convert.ToString(sdr.GetValue(0)),
                        Name = Convert.ToString(sdr.GetValue(01)),
                        Mobile = Convert.ToString(sdr.GetValue(2)),
                        Age = (sdr.GetValue(3) != DBNull.Value) ? Convert.ToInt32(sdr.GetValue(3)) : 0,
                        Birthday = (sdr.GetValue(4) != DBNull.Value) ? Convert.ToDateTime(sdr.GetValue(4)) : (DateTime?)null
                        Address = Convert.ToString(sdr.GetValue(5)),
                        Country = Convert.ToString(sdr.GetValue(6))
                    });
            }

            return Ok(web);
        }
    }

    [HttpGet]
    public IHttpActionResult GetCountry(string country)
    {
        List<webapi> web = new List<webapi>();

        using (SqlCommand cmd = new SqlCommand("SELECT U.UserID, U.Name, U.Mobile, U.Age, U.Birthday, A.Address, A.Country From tbluser U inner join tblAddress A where charindex(@country, A.Country)=1 order by U.UserId", connection))
        {
            cmd.Parameters.Add("@country", SqlDbType.VarChar);
            cmd.Parameters["@country"].Value = country.ToString();

            using (SqlDataReader sdr = cmd.ExecuteReader())
            {
                while (sdr.Read())
                {
                    web.Add(new webapi()
                        {
                            UserId = Convert.ToString(sdr.GetValue(0)),
                            Name = Convert.ToString(sdr.GetValue(01)),
                            Mobile = Convert.ToString(sdr.GetValue(2)),
                            Age = (sdr.GetValue(3) != DBNull.Value) ? Convert.ToInt32(sdr.GetValue(3)) : 0,
                            Birthday = (sdr.GetValue(4) != DBNull.Value) ? Convert.ToDateTime(sdr.GetValue(4)) : (DateTime?)null
                            Address = Convert.ToString(sdr.GetValue(5)),
                            Country = Convert.ToString(sdr.GetValue(6))
                        });
                }
            }

            return Ok(web);
        }
    }
} 

Class:

public class webapi
{
    public string UserId { get; set; }
    public string Name { get; set; }
    public string Mobile { get; set; }
    public int Age { get; set; }
    public DateTime? Birthday { get; set; }
    public string Address { get; set; }
    public string Country { get; set; }
}