PHP oop error with pdo - Call to a member function prepare() on a non-object

Question

am new to PHP-OOP and working with the pdo am getting the following errors

Warning: PDO::__construct() expects parameter 3 to be string, array given in C:\xampp\htdocs\ooplogin\classes\DB.php on line 12

connected

Fatal error: Call to a member function prepare() on a non-object in C:\xampp\htdocs\ooplogin\classes\DB.php on line 28

Here's my /db.php

<?php
class DB{
 private static $_instance = null;
 private $_pdo, 
   $_query, 
   $_error = false, 
   $_results, 
   $_count = 0;

 private function __construct(){
  try {
   $this->_pdo = new PDO('mysql:host=' . Config::get('mysql/host') . ';dbname='. Config::get('mysql/db'), Config::get('mysql/username'), Config::get('mysql/passsword'));
   echo "connected";
  } catch (PDOException $e) {
   die($e->getMessage());
  }
 }

 public static function getInstance() {
  if (!isset(self::$_instance)) {
   self::$_instance = new DB();
  }
  return self::$_instance;
 }

 public function query($sql, $params = array()) {
  $this->_error = false;
  if($this->_query = $this->_pdo->prepare($sql)) {
   $x = 1;
   if (count($params)) {
    foreach ($params as $param) {
     $this->_query->bindValue($x, $params);
     $x++;
    }
   }

   if ($this->_query->execute()) {
    $this->_results = $this->_query->fetchAll(PDO::FETCH_OBJ);
    $this->_count = $this->_query->rowCount();
   } else {
    $this->_error = true;
   }
  }
  return $this;
 }
 public function error(){
  return $this->_error; 
 }
}

config.php

<?php
class Config{
 public static function get($path = null){
  if($path){
   $config=$GLOBALS['config'];
   $path = explode('/',$path);

   foreach ($path as $bit) {
    if(isset($config[$bit])){
     $config = $config[$bit];     
    }
   }
   return $config;
  }
  return false;
 }
}

init.php

<?php
session_start();

$GLOBALS['config'] = array(
  'mysql' =>array(
   'host' => '127.0.0.1',
   'username'=>'root',
   'password' =>'',
   'db' =>'spyroll'
  ),
  'remember' =>array(
   'cookie_name' =>'hash',
   'cookie_expiry' =>604800
  ),
  'session' =>array(
   'session_name' => 'user'
  )
 );

spl_autoload_register(function($class){
 require_once 'classes/'. $class . '.php';
});

index.php

<?php
require_once 'core/init.php';

$user = DB::getInstance()->query("SELECT username FROM users WHERE username = ?", array('alex'));

if($user->error()) {
 echo 'no user';
} else {
 echo 'OK!';
}

}

Thanks a ton in advance for your help. I really need to solve this as soon as possible. -syed

Your `Config::get()` is returning an array, but the connection requires a string like `localhost`. Then the fatal error happens because your connection has failed. — Rasclatt, Jan 26 '15 at 05:26
That `Config` class/method seems a bit elaborate for just putting in PDO credentials. Can't you just simply put the connection credentials in manually? — Rasclatt, Jan 26 '15 at 05:30
For instance, in the `__construct()` of the `DB` class, just write manually the db info like: `__construct($host = 'localhost',$username = 'username',$password = 'password',$dbname = 'db_name')` — Rasclatt, Jan 26 '15 at 05:32
You have a typo in `Config::get('mysql/passsword')` -- too many `s`s. Any chance that's all it is? — elixenide, Jan 26 '15 at 05:34
I suggest use http://idiorm.readthedocs.org/en/latest/ instead your `class DB`, because it contain all needed actions. Just try it:) — stepozer, Jan 26 '15 at 09:08
Don't wrap your PHP code with snippet tag. All your questions have snippets that are not working and will never work. — Michael Sivolobov, Jun 02 '15 at 14:44

score 0 · Answer 1 · answered Jan 26 '15 at 15:42

There is just a typo in your password request. Try

$this->_pdo = new PDO('mysql:host=' . Config::get('mysql/host') . ';dbname='. Config::get('mysql/db'), Config::get('mysql/username'), Config::get('mysql/password'));

instead of

$this->_pdo = new PDO('mysql:host=' . Config::get('mysql/host') . ';dbname='. Config::get('mysql/db'), Config::get('mysql/username'), Config::get('mysql/pass**s**word'));

What happens? If your "config path" is not found, your Config::get method returns the full configuration array. Maybe you can throw an exception if the key is not found... or you return false (as you also do if $path is not given):

<?php
class Config{
    public static function get($path = null){
        if($path){
            $config=$GLOBALS['config'];
            $path = explode('/',$path);

            $result = false;
            foreach ($path as $bit) {               
                if(isset($config[$bit])){
                    $result = $config[$bit];                    
                }
            }
            return $result;
        }
        return false;
    }
}

Also your Config::get method does not make sense in this case. It is not able to handle more complex arrays, but it is too complex to handle such simple 2-dimensional arrays. Maybe you can use a method like Config::get($key, $value)?

<?php
class Config{
    public static function get($key, $value){
        if (isset($GLOBALS['config'][$key]) && isset($GLOBALS['config'][$key][$value]))
            return $GLOBALS['config'][$key][$value];
        else {
            trigger_error('Unknown configuration entry.', E_USER_WARNING);
            return false;
        }
    }
}

Thanks a lot.. for all the helpful tips.. really appreciate it...! please if you get time can u help me with this.. [link](http://stackoverflow.com/questions/28199995/php-oop-issue-with-database) — syed_h, Jan 28 '15 at 18:49

PHP oop error with pdo - Call to a member function prepare() on a non-object

1 Answers1