php - PDO extend for a crud querys and Fatal error -

i'm trying make query class crud , want extend connection other class, error : fatal error: call member function prepare() on non-object !? miss ? or stupito extend ?

here mysql_connection extend querys class. both different php files.

class mysql_connection extends querys {      protected $dbh = null;          function __construct()         {                 try                 {                     $this->dbh = new pdo('mysql:host=host; dbname=db','user','pass', array(pdo::mysql_attr_init_command=> 'set names utf8'));                     $this->dbh->setattribute(pdo::attr_errmode, pdo::errmode_exception);                     $this->dbh->setattribute(pdo::attr_default_fetch_mode, pdo::fetch_assoc);                  }                 catch(pdoexception $e)                 {                     $this->dbh = null;                      print('error on connection'.$e->getmessage());                     die();                 }         } } 

and here query class

class querys{      function getdata()     {         $sql = "select * db";          $result = $dbh->prepare($sql);          $result = execute();          $data = $result->fetch(pdo::fetch_assoc);                      return = $data;     }  } 

you need call

$this->dbh->prepare($sql); 

instead of

$dbh->prepare($sql); 

you need replace

return = $data; 

with

return $data; 

remember return statement, not variable!

furthermore, mysql_connection extends querys incorrect use of inheritance. a extends b means a subtype of b.

using real-world example, dog subtype of animal. because dog animal, right? dog extends animal correct.

however, connection not query!

i recommend read bit inheritance , object oriented programming. ;)