SQL Not Executing : The first SQL is executing but the second one doesn't seem to work.
When i change the query to the first one it works just fine but when I put it like that it doesn't seem to work for some reason.

I've just started learning MySQL i'm really struggling with this one and understanding the language.

     //Classic One that checks if the hwid is there
        public void checkHWID(string HWID)
        {
            string line;
            using (SqlConnection con = new SqlConnection(connectionString))
            {

                con.Open();

                using (SqlCommand cmd = new SqlCommand("SELECT * FROM Users WHERE HWID = @HWID", con))
                {
                    cmd.Parameters.AddWithValue("@HWID", HWID);
                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        if (reader.Read())
                        {
                            line = reader[1].ToString();
                            Console.Write(line);
                            con.Close();
                        }
                        else
                        {
                            updateHWID(HWID);
                        }

                    }

                }

            } 
        }
        //This one doesn't seem to update the hwid but when i change the query to the first one it works just fine
        public void updateHWID(String HWID)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                using (SqlCommand command = new SqlCommand("INSERT INTO USERS(hwid) VALUES(@HWID)", connection))
                {
                    command.Parameters.AddWithValue("@HWID", HWID);
                    connection.Close();
                }
            }
        }