Extending MySQLi

Question

I've run into problems extending the MySQLi class. It won't let me add any properties.

class MySQLii extends MySQLi {

 public $database;

 public function MySQLii($host, $username, $password, $database){

  // Initialize MySQLi
  parent::MySQLi($host, $username, $password, $database);

  // Save database name
  $this->database = $database;

 }

}

$mysqlii = new MySQLii('localhost', 'root', 'password', 'database');

var_dump($mysqlii);

object(MySQLii)#1 (17) {
["affected_rows"]=> int(0)
["client_info"]=> string(48) "mysqlnd 5.0.5-dev - 081106 - $Revision: 289630 $"
["client_version"]=> int(50005)
["connect_errno"]=> int(0)
["connect_error"]=> NULL
["errno"]=> int(0) ["error"]=>
string(0) "" ["field_count"]=>
int(0) ["host_info"]=> string(42) "MySQL host info: Localhost via UNIX socket" ["info"]=> NULL
["insert_id"]=> int(0)
["server_info"]=> string(6) "5.1.44" ["server_version"]=> int(50144)
["sqlstate"]=> string(5) "00000"
["protocol_version"]=> int(10)
["thread_id"]=> int(4019)
["warning_count"]=> int(0) }

Note the absence of the database property I added in the MySQLii constructor. Am I missing something?

Answer 1

Hm, either I am missing something or you named your constructor MySQLii instead of __construct. (This is not Java ;))

Renaming it appropriately could solve the problem as it looks as if your constructor is not called.

Answer 2

Apparently extending the MySQLi class makes it impossible to add additional properties. Bad PHP. Bad.

Answer 3

I've just made a wrapper to MySQLi and MySQLi_STMT by extending both classes (as per PHP 5.3 and 5.2). I can confirm that while the variables don't appear when you dump it with var_dump, the class methods accesses the variables like any other normal object without problems.

class Foo extends MySQLi
{
    public $var = 'blah';

    public function blah()
    {
        echo $this->var;
    }
}

$foo = new Foo();
echo $foo->var;
$foo->blah();

Accessing the variable from outside of the class also works as expected. As long as you don't normally use var_dump to figure out which variable exists or other unorthodox functionality, just code as you normally do and you'll have no problems.