Call to a member function count() on a non-object. From one .php to another

Question

So I have been getting this fatal error: "Fatal error: Call to a member function count() on a non-object in /Applications/XAMPP/xamppfiles/htdocs/website/index.php on line 6". I will just give you a large portion go my code just in case.

Here is 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/password'));      
    } 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, $param);
                $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 action($action, $table, $where = array()) {
    if(count($where) === 3) {
        $operators = array('=', '>', '<', '>=', '<=');

        $field      = $where[0];
        $operator = $where[1];
        $value      = $where[2];

        if(in_array($operator, $operators)) {
            $sql = "{$action} * FROM {$table} WHERE {$field} {$operator} ?";
            if(!$this->query($sql, array($value))->error()) {
                return $this;
            }
        }
    }
    return false;
}

public function get($table, $where) {
    return $this->action('SELECT*', $table, $where);
}

public function delete($table, $where) {
    return $this->action('DELETE', $table, $where);
}

public function error() {
    return $this->_error;
}

public function count() {
    return $this->_count;
}

}

Here is my index.php

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

$user = DB::getInstance()->get('users', array('username', '=', 'alex'));

if(!$user->count()) {
    echo 'No user';
} else {
   echo 'OK!';
}

What am I doing wrong?

`$user` is not an object, check what it is by `var_dump($user);`. And because it is not an object, you cannot call its method by `->count()` — Cheery, Oct 19 '14 at 22:51

score 0 · Answer 1 · answered Oct 19 '14 at 22:57

You have an error in your get() method that will lead to an sql statement of:

SELECT* * FROM ....

You can remove the * from your get method or remove it from your action method and add a space in your get method.

You probably need the latter option for your delete method to work:

public function get($table, $where) {
    return $this->action('SELECT *', $table, $where);
}

and:

...
$sql = "{$action} FROM {$table} WHERE {$field} {$operator} ?";
...

Apart from that you are assuming that PDO will throw exceptions, but you need to tell PDO that first.

You can add that option in your constructor:

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

Now PDO will throw an exception when something goes wrong.

score 0 · Answer 2 · edited May 23 '17 at 10:33

The error message is telling you that $user is a non-object. Looking at the codes of your action() function, my guess is that your $user is set to false, because of a SQL syntax error caused by:

public function get($table, $where) {
  return $this->action('SELECT*', $table, $where); // there is an extra asterisk here

}

And

$sql = "{$action} * FROM {$table} WHERE {$field} {$operator} ?";

Notice the extra asterisk in your SELECT clause.

Call to a member function count() on a non-object. From one .php to another

2 Answers2