Undefined variable: dbh, what is wrong with the code in my application?

Question

I'm getting the following error when trying to add a pdo database connection to my MVC application and I can't figure out what is wrong with my code. It works if I just include the dbconnection.php and create a new instance whenever I need to. But I really want to learn how to work with MVC. I'm quite new in php and I'm just started with MVC. Can anyone figure out what I'm doing wrong? And I don't wanna use globals so I'm completely stuck. Here is the error:

Notice: Undefined variable: dbh in C:\xampp\htdocs\me1520\php\uppgift-MVC\model\MovieModel.php on line 17

Fatal error: Call to a member function beginTransaction() on a non-object in C:\xampp\htdocs\me1520\php\uppgift-MVC\model\MovieModel.php on line 17

This is my dbconnection:

class DbConnection {

    private $host   = DB_HOST;
    private $dbuser = DB_USER;
    private $dbpass = DB_PASS;
    private $dbname = DB_NAME;

    private $dbh;

    public function dbcon($host, $dbuser, $dbpw, $db) {
            $pre = 'mysql:host='.$host.';dbname='.$db.;

            $this->dbh = new PDO($pre, $dbuser, $dbpw, array(PDO::ATTR_PERSISTENT => true));
            $this->dbh->exec('SET CHARACTER SET utf8',);
            return $this->dbh;
        }
}

And here is my basemodel code:

class BaseModel {
    protected $dbh;

    public function __construct()
    {
        $database = new DbConnection();
        $this->dbh = $database->dbcon('localhost', 'root', '6662257', 'mvc');
    }
}

And this is my moviemodel code:

include_once 'BaseModel.php';
include_once 'Movie.php';

class MovieModel extends BaseModel {

    public function __construct()
    {
        parent::__construct();
    }

    public function getMovieList() {
        try {

            $dbh->beginTransaction();

            $sql = $dbh->prepare("SELECT * FROM movies ORDER BY movie_id");
            $sql->execute();

            $movies = array();

            while($row = $sql->fetch()){    
                $id = $row['movie_id'];
                $title = $row['movie_title'];
                $description = $row['movie_des'];
                $link = $row['movie_link'];
                $movies[$title] = new Movie($id, $title, $description, $link);
            }

            return $movies;
            $dbh->commit();
        }

        catch (Execption $e) {
            $dbh->rollback();
        }

    }

score 2 · Accepted Answer · answered Feb 13 '14 at 15:15

2

You need to use $this->dbh in MovieModel, not $dbh.

I also should mention that you don't need transactions for a SELECT query. Drop beginTransaction(), commit() and rollback() calls from getMovieList().

Also you don't need a constructor if it only calls the parent's constructor. This behaviour you have by default. Drop __construct() from MovieModel

answered Feb 13 '14 at 15:15

hek2mgl

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How embarassing, Well as I said I'm quite new so easy mistakes are happening a bit to often :) This works great, thank you very much!! Okey I'll drop the transaction thank you. – Bondenn Feb 13 '14 at 15:17

Undefined variable: dbh, what is wrong with the code in my application?

1 Answers1