在CodeIgniter中更新产品图片

I'm trying to make an update form so users are able to change a product picture. The form works fine everything gets updated except for the picture.

Also I have a product_foto_thumb and a normal product_foto so I don't know how to do that in my view.

This is how I have it in my view:

<input type="file" name="userfile"/>
<td>
    <?php echo form_input(array('type'=>'hidden','id'=>'product_foto', 'name'=>'product_foto', 'value' => $product['product_foto']));?>
</td>

But I guess I also need an input type for the product_foto_thumb?

And this is my update controller function:

public function update_product() 
{

    $id= $this->input->post('product_id');
    $data = array(
        'product_naam' => $this->input->post('product_naam'),
        'category_id' => $this->input->post('category_id'),
        'ophaal_plaats' => $this->input->post('ophaal_plaats'),
        'product_beschrijving' => $this->input->post('product_beschrijving'),
        'product_foto_thumb' => 'thumb_'.$dataThumb["raw_name"].$dataThumb['file_ext'],
        'product_foto' => 'new_'.$data["raw_name"].$data['file_ext'],
    );
    $this->Update_product_model->update_product_function($id,$data);
}

So the form works but except when I select a new picture and I submit the form, the old picture is removed and there is no new picture on the product. Can anyone help me?

Try this code, definitely will help you.

if($this->input->post('submit')){
    if(($_FILES['userfile'])){
        $errors= array();
        $file_name = $_FILES['userfile']['name'];
        $file_size = $_FILES['userfile']['size'];
        $file_tmp = $_FILES['userfile']['tmp_name'];
        $file_type = $_FILES['userfile']['type'];
        $ext = pathinfo($file_name, PATHINFO_EXTENSION);
        $expensions= array("jpeg","jpg","png");
        // this is used for unique file name always
        $mtime = uniqid(microtime());
        $uniqueid =  substr($mtime,2,8);
        $filename = $uniqueid.'.'.$ext;

        if(in_array($ext,$expensions)=== false){
         $errors[]="extension not allowed, please choose a JPEG or PNG file.";
        }
        if($file_size > 2097152) {
         $errors[]='File size must be excately 2 MB';
        }
        if(empty($errors)==true) {
         move_uploaded_file($file_tmp,"upload_folder_name_here/".$filename);
        }
    }
    $id= $this->input->post('product_id');
    $data = array(
        'product_naam' => $this->input->post('product_naam'),
        'category_id' => $this->input->post('category_id'),
        'ophaal_plaats' => $this->input->post('ophaal_plaats'),
        'product_beschrijving' => $this->input->post('product_beschrijving'),
        'product_foto_thumb' => 'thumb_'.$filename,
        'product_foto' => 'new_'.$filename,
    );
    $this->Update_product_model->update_product_function($id,$data);
}