Question

I am extending a class from mysqli, but I am not sure if I am doing correctly when I want to close the db connection:

class database extends mysqli
{
    public function __construct($hostname = null,$username= null,$password = null,$database = null,$port = null, $socket = null)
    {
        $hostname = $hostname !== null ? $hostname : ini_get("mysqli.default_host");
        $username = $username !== null ? $username : ini_get("mysqli.default_user");
        $password = $password !== null ? $password : ini_get("mysqli.default_pw");
        $database = $database !== null ? $database : "";
        $port     = $port     !== null ? $port     : ini_get("mysqli.default_port");
        $socket   = $socket   !== null ? $socket   : ini_get("mysqli.default_socket");

        parent::__construct($hostname,$username,$password,$database,$port,$socket);


        # Check for connection error

        if (mysqli_connect_errno()) 
        {
            printf("Connect failed: %s\n", mysqli_connect_error());
            exit();
        }
    }


    #closes the database connection when object is destroyed.
    public function __destruct()
    {
        return parent::close();
        //echo "Destructor Called";
    }
}

do I have put return in front of parent::close();?

return parent::close();

or this will do?

public function __destruct()
        {
            parent::close();

        }

Thanks.

Answer 1

The idea with a destructor is that it is automatically called when the object goes out of scope. As such, there will be nothing to assign a return value to.

The best practice is for destructors (and constructors) to not return anything (void).

Program code should never call the destructor directly.

Edit: So to directly answer your question, use your second example

public function __destruct()
{
    parent::close();
}

---

Regarding exceptions, try something like this in your constructor

if (mysqli_connect_errno()) {
    throw new Exception('Connect failed: ' . mysqli_connect_error());
}

To catch the exception, simply use a try / catch block, eg

try {
    $database = new database();
} catch (Exception $ex) {
    echo $ex->getMessage(); // or whatever
}