nodejs + mysql: how can i reopen mysql after end()?

code as follows:

var mysql      = require('mysql');
var connection = mysql.createConnection({
  host      : 'localhost',
  port      :"3306",
  database  :"mydb",
  user      : 'root',
  password  : '007007',
});
var isCon = true;
connection.connect(
    function  (err) {
        console.log(isCon);
        if (err) {
           isCon=false;
           console.error("error connecting :"+err);
           return;
       };
   }
   );
if(isCon){
    connection.query('select * from tb_items', function(err, result) {
        if (err) throw err;
        console.log('The solution is: ', result);
        console.log('The typeof solution is ',typeof(result));
        debugger;
    });
    connection.end();
}

connection.connect(
    function  (err) {
        console.log(isCon);
        if (err) {
           isCon=false;
           console.error("error connecting :"+err);
           return;
       };
   }
   );
if(isCon){
    connection.query('select * from tb_items', function(err, result) {
        if (err) throw err;
        console.log('The solution is: ', result);
        console.log('The typeof solution is ',typeof(result));
        debugger;
    });
    connection.end();
}

i just open()-->connect()-->query()-->end(),then did it again,but second time , there is a error : Error:Could not enqueue Handshake after invoking quiting . question : maybe i can't reopen it after end().but i just wanna kwon ,if i end(),how can i reopen it?