Question

I am learning OOPS concept and also using PDO , but really stuck in very basic problem, please look into my code and tell me what i am doing wrong and how to optimize this code.

###class.db.php

class DB
{
    public $dbh;
    private $qry;
    
    public function __construct($user ='root',$pass = '')
    {
        try {
            $this->dbh = new PDO('mysql:host=localhost;dbname=parixan',$user,$pass);
            $this->dbh->exec("SET CHARACTER SET utf8"); 
            echo "connected";
        } catch(Exception $e){
            die("Unable to connect: " . $e->getMessage());
        }       
    }
} 

###class.user.php

class User
{
    public $db;
    protected $_table ='tbl_user';
    public function __construct($dbh)
    {
        $this->db = $dbh;       
    }
    public function getUserDetails($id) //line #10
    {
        $qry = "SELECT * FROM $this->_table WHERE id = :userID LIMIT 1";
        $stmt = $this->db->prepare($qry); //line #13
        $stmt->bindParam(':userID',$id,PDO::PARAM_INT);  
        if ($stmt->execute()) {
        while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
            echo "<pre>";print_r($row);
        }
    }

    }
    
}

###user.php

include_once('class.user.php');
include_once('class.db.php');
$dbh = new DB();
$obj_user = new User($dbh);
$obj_user ->getUserDetails(1);

on running user.php I got this one

connected Fatal error: Call to undefined method DB::prepare() in
C:\xampp\htdocs\oops\class.user.php on line 13

Thanks.

Answer 1

Within the User object, $this->db is a reference to an object of the DB class. This class does not implement a prepare method, so there is none available when you attempt to call it with $stmt = $this->db->prepare($qry);.

If you persist with your current class design, you need to create such a function:

public function prepare($qry) {
    return $this->dbh->prepare($qry);
}

This means you will now have a PDOStatement object, on which you can call bindParam and execute.