Question

I’m trying to create a simple class based on my database PDO class that I can say “get this id” and it will print the info. I’m trying to do this in “qu” but get the following error: “Call to undefined method qu::get()”.

There’s probably a mixture of problems so any help here would be awesome. Thanks a lot!!

class db {

   protected static $conn;
   private function __construct(){}

   public static function connect() {

      if (!isset(self::$conn)) {
           self::$conn = new PDO('mysql:host=localhost;dbname=database', DB_USER, DB_PASSWORD);
      }

      return self::$conn;
   }

}

    class qu {

    private $db;
    function quconn (&$db){
        $this->db = &$db;
    }

    private static function getq($id){

        $sql="SELECT * FROM table WHERE id=:id";
        $stmt = self::quconn()->prepare($sql);
        $stmt->execute(array(':id'=> $id));
        $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
        return $result;

    }   

}

//$data = db::connect()->query("SELECT * FROM table")->fetchAll(); // this works

$data = qu::getq("22"); //can i use something like this? this causes the error
print_r($data);

Answer 1

function getq of class qu should be marked with public access modifier.
Otherwise the following row will fail as getq is a private function

 $data = qu::getq("22");

Second and issue in this code

 function quconn (&$db){
    $this->db = &$db;
}

As you enter function quconn from a static content $this is unavailable.

Use self::$db instead.

For class qu follow the same structure of class db wich is a singleton mnagament class.

I also suggest to clarify yourself differences between $this and self, static contest etc..

Php offiacial documentation offers al lot about

Also i don’t think you need passing-by-reference method:
try to rewrite the quconn function as follows:

 function quconn ($db){
   self::$db = $db;

}

By the way i don’t thing the class qu is well “engineered”
Even if you correct the passing-by-reference-problem this instruction won’t work:

$stmt = self::quconn()->prepare($sql);

You are invoking the prepare function on the result of the invocation to quconn, which doesn’t return anything…

I suggest:

 $stmt = db::connect()->prepare($sql);

this get the PDP instance and call the prapare method….