title: Node-mysql error PROTOCOL_ENQUEUE_A FTER_DESTROY
body: <p>That is my code:</p>
  
  <pre><code>var mysql      = require('mysql');
  var client     = mysql.createConnection({
    host     : 'somehost',
    port     : 'myport',
    user     : 'username',
    password : 'password',
    database : 'mydb'
  });
  //get posts
  function get(callback){
    var result = [];
    var queryString = "SELECT id,title,short_text,creation_date FROM posts");
    var query = client.query(queryString);
    query
    .on('error', function(err){
      callback(err, null);
    })
    .on('fields', function(fields){
      // the field packets for the rows to follow
    })
    .on('result', function(row){
      result.push(row);
    })
    .on('end', function(){
      callback(null, result);
      // all rows have been received
    });
  }
  </code></pre>
  
  <p>It works succees sometimes but sometimes return error:
          { [Error: Cannot enqueue Query after being destroyed.] code: 'PROTOCOL_ENQUEUE_A
  FTER_DESTROY', fatal: false }</p>
  
  <p>Who can say what's wrong?</p>