使用PDO建立与本地主机数据库的连接的问题

Question

I am learning PHP and trying to establish a connection with my database so i can do simple data input/output. I am learning object oriented PHP. I have an index.php which calls the database.php file. The database.php file has all the connection material. The database has been created on my localhost. I am trying to connect to it. Using the PDO .

The code in the database.php file is :

<?php 

class Database{

    private $host = 'localhost';
    private $user = 'root';
    private $password = '';
    private $dbname = 'edunoix';

    private $dbh;
    private $error;
    private $stmt;

    public function __construct(){
        //dsn or connection string
        $dsn = 'myql:host='. $this->$host . ';dbname=' . $this->dbname;
        //set pdo options
        $options = array(
            PDO::ATTR_PERSISTENT =>true,
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
        );
        //create a new pdo
        try{
            $this->dbh = new PDO($dsn, $this->user, $this->pass, $options);
        }catch(PDOEception $e){
            $this->error = $e->getMessage();
        }
    }
}

?>

When i compile and run i get the following error:

   ( ! ) Notice: Undefined variable: host in C:\wamp\www\oophp\pdo\classes\Database.php on line 16
    Call Stack
    #   Time    Memory  Function    Location
    1   0.0005  237960  {main}( )   ..\index.php:0
    2   0.0010  247584  Database->__construct( )    ..\index.php:5


( ! ) Fatal error: Cannot access empty property in C:\wamp\www\oophp\pdo\classes\Database.php on line 16
Call Stack
#   Time    Memory  Function    Location
1   0.0005  237960  {main}( )   ..\index.php:0
2   0.0010  247584  Database->__construct( )    ..\index.php:5

Please tell me how can i resolve this. I am new and following an online tutorial so please help me correct the issue. Any help will be appriciated

Answer 1

use this code: if you want to upgrade your PDO class.BaseDao{

protected $user="root";
protected $pass="";
protected $name="mydatabase";
protected $dbh=null;

    function openConn(){
        $this->dbh=new PDO("mysql:host=localhost;dbname=".$this->name,$this->user,$this->pass);

        }
     function closeConn(){
 $this->dbh=null;

    }
}