How to insert custom data in database using Opencart - insert

Question

Am creating my store using Opencart. Here am creating a custom page called sales_performance.
Am trying to insert some value in database.
But i can't insert the data, how can i do that?.
And also it not showing error
Following my code:
Controller
sales_performance.php
<?php
class ControllerProductSalesPerformance extends Controller
{
private $error = array();
private $data = array();
public function index()
{
$this->load->language('product/allproduct');
$this->document->setTitle($this->language->get('Sales Performance'));
$this->load->model('catalog/allproduct');
$data['action']=$this->url->link('product/sales_performance','','SSL');
$this->data['text_list'] = $this->language->get('text_list');
$this->data['text_no_results'] = $this->language->get('text_no_results');
$this->data['text_confirm'] = $this->language->get('text_confirm');
$this->data['text_missing'] = $this->language->get('text_missing');
$this->data['column_order_id'] = $this->language->get('column_order_id');
$this->data['column_customer'] = $this->language->get('column_customer');
$this->data['column_status'] = $this->language->get('column_status');
$this->data['column_total'] = $this->language->get('column_total');
$this->data['column_date_added'] = $this->language->get('column_date_added');
$this->data['column_date_modified'] = $this->language->get('column_date_modified');
$this->data['column_action'] = $this->language->get('column_action');
$this->data['entry_return_id'] = $this->language->get('entry_return_id');
$this->data['entry_order_id'] = $this->language->get('entry_order_id');
$this->data['entry_customer'] = $this->language->get('entry_customer');
$this->data['entry_order_status'] = $this->language->get('entry_order_status');
$this->data['entry_total'] = $this->language->get('entry_total');
$this->data['entry_date_added'] = $this->language->get('entry_date_added');
$this->data['entry_date_modified'] = $this->language->get('entry_date_modified');
$this->data['button_invoice_print'] = $this->language->get('button_invoice_print');
$this->data['button_shipping_print'] = $this->language->get('button_shipping_print');
$this->data['button_add'] = $this->language->get('button_add');
$this->data['button_edit'] = $this->language->get('button_edit');
$this->data['button_delete'] = $this->language->get('button_delete');
$this->data['button_filter'] = $this->language->get('button_filter');
$this->data['button_view'] = $this->language->get('button_view');
//$data['token'] = $this->session->data['token'];
$pagination = new Pagination();
//$pagination->total = $order_total;
//$pagination->page = $page;
$data['pagination'] = $pagination->render();
$this->data['sort'] = $sort;
$this->data['order'] = $order;
$this->data['header'] = $this->load->controller('common/header');
$this->data['column_left'] = $this->load->controller('common/column_left');
$this->data['footer'] = $this->load->controller('common/footer');
$this->response->setOutput($this->load->view('default/template/product/sales_performance.tpl', $this->data));
}
public function insertSelectedCustomer()
{
#####Add sales persion achievement####
if ($this->request->server['REQUEST_METHOD'] == 'POST')
{
$date = $_GET['date'];
$sales_person_id = $_GET['sales_person_id'];
$sales_person_name = $_GET['sales_person_name'];
$customer_id = $_GET['customer_id'];
$customer_name = $_GET['customer_name'];
$achievement = $_GET['achievement'];
$query = $this->db->query("insert into ".DB_PREFIX."sales_person_achievement('date') value('".$date."')");
if($query==false)
{
echo ''.mysql_error();
}
}
##### Add sales persion achievement ####
}
}
This is my tpl file
sales_performance.tpl
<form action="<?php echo $action; ?>" method="POST" class="form-inline" enctype="multipart/form-data">
<div class="form-group">
<label for="">Select Date:</label>
<input type="text" name="date" id="datepicker" class="form-control" placeholder="Select Date">
<input type="hidden" name="sales_person_id" value="<?php echo $sales_person1['customer_id']; ?>">
<input type="hidden" name="sales_person_name" value="<?php echo $sales_person1['name']; ?>">
<input type="hidden" name="customer_id" value="<?php echo $customer['customer_id'];; ?>">
<input type="hidden" name="customer_name" value="<?php echo $customer['name'];; ?>">
</div>
<div class="form-group">
<label for="">Fill Achievement Amonut:</label>
<input type="number" name="achievement" class="form-control" placeholder="Achievement Amount">
</div>
<div class="form-group">
<input type="submit" id="saveachievement" name="save" class="btn btn-primary">
</div>
</form>
<script type="text/javascript">
$('#saveachievement').on('click', function() {
var date = document.getElementsByName('date')[0].value;
var sales_person_id = document.getElementsByName('sales_person_id')[0].value;
var sales_person_name = document.getElementsByName('sales_person_name')[0].value;
var customer_id = document.getElementsByName('customer_id')[0].value;
var customer_name = document.getElementsByName('customer_name')[0].value;
var achievement = document.getElementsByName('achievement')[0].value;
//alert(achievement);
location="index.php?route=product/sales_performance&sales_person_id="+sales_person_id+"&customer_id="+customer_id;
});
</script>

Answer 1

Actually am miss spelling for value
$query = $this->db->query("insert into ".DB_PREFIX."sales_person_achievement('date') value('".$date."')");
change To
$query = $this->db->query("insert into ".DB_PREFIX."sales_person_achievement('date') values('".$date."')");
i mean value change to values
Now its working.