无法使用codeigniter在数据库中输入值

Question

该表单的验证工作正常，但是当我尝试插入和提交时，数据没有存储在数据库中。我不明白我遇到了哪个问题。

Home.php（控制器文件）

<?php  
    defined('BASEPATH') OR exit('No direct script access allowed');  

    class Home extends CI_Controller {
        public function __construct() 
        {
            parent::__construct();

            //load database libray manually
            $this->load->database();

            //load Model
            $this->load->model('Contact_model');

            // load form and url helpers
            $this->load->helper(array('form', 'url'));

            // load form_validation library
            $this->load->library('form_validation');
        }

        public function contact()  
        {  
            // Basic validation
            $this->form_validation->set_rules('name', 'Name', 'required');
            $this->form_validation->set_rules('email', 'Email', 'required|valid_email');
            $this->form_validation->set_rules('subject', 'Subject', 'required');
            $this->form_validation->set_rules('message', 'Message', 'required');

            if ($this->form_validation->run() == FALSE)
            {
                $this->load->helper('url');
                $this->load->view('header');
                $this->load->view('contact'); 
                $this->load->view('footer');
            }
            else
            {
                /* load success template...
                echo "Thanks For Contacting!";*/
                //insert
                if($this->input->post('submit'))
                {
                    $name=$this->input->post('name');
                    $email=$this->input->post('email');
                    $subject=$this->input->post('subject');
                    $message=$this->input->post('message');
                    $this->Contact_model->saverecords($name,$email,$subject,$message);  
                    echo "Records Saved Successfully";
                }
            }
        }

    }  
?>

contact_model.php（模型文件）

<?php
    class Contact_model extends CI_Model 
    {
        //Insert
        function saverecords($name,$email,$subject,$message)
        {
            $query="insert into contact values('', '$name', '$email', '$subject', '$message')";
            $this->db->query($query);
        }
    }
?>