Two PDO connection error

Question

Hey guys i have recently moved over to PDO and OOP and having some problems with the connection statement. The errors i am receiving are;

Notice: Undefined variable: db_host in C:\Users\PC\Documents\XAMPP\htdocs\libs\class.Manage.php on line 14

Fatal error: Cannot access empty property in C:\Users\PC\Documents\XAMPP\htdocs\libs\class.Manage.php on line 14

class ManageHits{

protected $link;
protected $db_host = "localhost";
protected $db_name = "ajaxrating";
protected $db_user = "userone";
protected $db_pass = "passwordone";

function __construct(){
    try{
    $this->link = new PDO($this->$db_host,$this->$db_name,$this->$db_user,$this->$db_pass);
        return $this->link;
    }
    catch(PDOException $e){
        return $e->getMessage;
    }
}

http://www.php.net/manual/en/language.oop5.visibility.php – Digital Chris Mar 12 '14 at 14:48 — Digital Chris, Mar 12 '14 at 14:48

score 0 · Answer 1 · answered Mar 12 '14 at 14:50

0

Read at least any tutorial on PDO.
Connect to PDO proper way, creating a PDO instance.

Pass that instance in your ManageHits class.

class ManageHits{

    protected $link;

    function __construct($db){
        $this->link = $db;
    }
}

answered Mar 12 '14 at 14:50

Your Common Sense

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score 0 · Answer 2 · answered Mar 12 '14 at 14:58

0

You are incorrectly calling your objects inside of new PDO():

$this->$db_host

should be

$this->db_host // and so forth

answered Mar 12 '14 at 14:58

MonkeyZeus

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score 0 · Accepted Answer · edited May 23 '17 at 12:13

You should read a step by step tutorial about PDO

Furthermore your code has many issues.

$e->getMessage; => $e->getMessage();
constructor should be public I assume ?
your variables should be private
constructors serve to instantiate the class
PDO
initialize your variables inside the constructor for compatibility

This is a working example assuming your connection info is correct:

class Con{

    protected $link;
    protected $db_host;
    protected $db_name;
    protected $db_user;
    protected $db_pass;

    public function __construct(){

        $this->db_host = "localhost";
        $this->db_name = "ajaxrating";
        $this->db_user = "userone";
        $this->db_pass = "passwordone";        

        try{

            $this->connection = new PDO("mysql:host=$this->db_host;dbname=$this->db_name", $this->db_user, $this->db_pass, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));
            echo 'Connection established!';
        }
        catch(PDOException $e){
            echo $e->getMessage();
        }
    }
}

$db = new Con();

thank you very much, will have to partake on a Youtube series on OOP and PDO — user3406014, Mar 12 '14 at 15:38

Two PDO connection error

3 Answers3