I tried to close the connection for the below query by using connection.close(). but it is not working, so how to close connection inside route file

var express = require('express');
var router = express.Router();
var connection  = require('../database.js');
var db  = require('../database.js');


 
/* GET home page. */
 router.get('/', function(req, res, next) {
  connection.query("Select users..... ",function(err,supervisorrows)     {

             if(err){
          req.flash('error', err); 
          res.render('View',{page_title:"Users - Node.js",supervisor:''});   
         }else{
            
             res.render('View',{page_title:"Users - Node.js",supervisor:supervisorrows.recordset});

         }                     
        });




 
module.exports = router;