Update and insert values to database using wcf rest and jquery

Hi,

Below is the code to update the table in sql database 

code for Interface

    [OperationContract]
        [WebGet(UriTemplate = "UpdatePresidentById/{id}",
            ResponseFormat = WebMessageFormat.Json)]
        void UpdatePresidentById(string id);

cs code

                       

 public void UpdatePresidentById(string id)

        {

            string connStr = @"Data Source=WIN-941LO3JBRJG\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True;";

            using (SqlConnection con = new SqlConnection(connStr))
            {
                string name = "zainobeta2";
                //DataTable dt = new DataTable();
                con.Open();
                SqlCommand cmd = new SqlCommand("Update tblEmployee set Name = @name where ID=@id", con);
                cmd.Parameters.AddWithValue("@name", name);
                cmd.Parameters.AddWithValue("@id", id);
                cmd.ExecuteNonQuery();
              //  con.Close();
                cmd.Dispose();
            }

        }

jquery code

function updatePresidentsDataById() {

    var data1 = {
        id: 2,
    };

    var serviceUri = _spPageContextInfo.webAbsoluteUrl +
        "/_vti_bin/PresidentsService.svc/UpdatePresidentById";
    $.ajax({
        method: 'POST',
        contentType: 'application/json;charset=utf-8',
        url: serviceUri,
        data: JSON.stringify(data1),
        dataType: "json",
        success:
            function (response) {
                alert('success');
            },
        error:
            function (err) {
                alert(JSON.stringify(err));
            }
    });

The table is not getting updated even after using PUT, also how to insert new values in the table using wcf rest jquery in sharepoint

Any suggestion plz, got stuck in above requirement for days.