Why doesn't the object get passed into the 'class property'?

This f开发者_如何学JAVAeels like its obvious... I've created these two classes in php but I'm struggling to understand why the object doesn't seem to be passed back.

    class DataAccess {

    function dbconnect($query){
        @ $db = new mysqli(MYHOST,MYDBUSER,DBUSERPASSWORD,MYDATABASE);
        if (mysqli_connect_errno()) {
            echo '<h1>there is an error with the database connection</h1>';
            exit;
        }    
        $result = $db->query($query);
        $db->close();
        return $result;
    }

and...

    class Run {

    public $getdata;
    public $jobdetails;

    function __construct(){
        $query = 'Select ID from jobs;';
        $getdata = new DataAccess();            

        $jobdetails = $getdata->dbconnect($query);
    }

    function getJobList(){
    print_r ($this->jobdetails);

    }
}

and I call using this:

$mything = new Run();

now if I print_r($result); from inside the dbconnect function it returns metadata, but if I do it once it's passed back to the Run class, it doesn't return anything. What am I missing?

$jobdetails is local to __construct, if you want to have it local to the instance, use $this->jobdetails

Change this

$jobdetails = $getdata->dbconnect($query);

To this:

$this->jobdetails = $getdata->dbconnect($query);

Firstly, you shouldn't make a DB connection for each query you run. Connect in the constructor and then the connection will be closed automatically when the script ends

class DataAccess {

    protected $_connection = null;

    function __construct() {
        $this->_connection = new mysqli(MYHOST,MYDBUSER,DBUSERPASSWORD,MYDATABASE);
        if (mysqli_connect_errno()) {
            echo '<h1>there is an error with the database connection</h1>';
            exit;
        }
    }

    function query($query){   
        return $this->_connection->query($query);
    }

}

Secondly, you're not setting the instance variable properly.

Change:

$jobdetails = $getdata->dbconnect($query);

To:

$this->jobdetails = $getdata->dbconnect($query);