如何使用php oop从mysql显示多行？

I'm a newbie in oop style. I start practicing it since last week and I make simple CRUD website. but i got a problem when i tried fetching rows from mysql db its always display 1 row.

my created a class named class.user.php

and it shows here:

include "db_config.php";

class User{


    private $db;
    public function __construct(){  
        $this->connect();

        }
        private function connect($db_connect=true){ 
            if ($db_connect){
                $this->db = new mysqli(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_DATABASE);
                if(mysqli_connect_errno()) {        
                    printf("DB Connect failed: %s
", mysqli_connect_error());
                    exit;
            }
        }       
    }
    public function get_tutoriallist(){
        $db = $this->db;
        if(empty($db)){
            $this->connect();
            $db = $this->db;
        }
        try {

            $stmt = $this->db->prepare('SELECT * FROM `topic`');
            $stmt->execute();
            $result = $stmt->get_result();
            $dataArray = array();
            while($row = $result->fetch_assoc()){
                $count_row = $result->num_rows;
                if ($count_row == 1) {
                $dataArray[] = $row;
                }
            }
            return ($dataArray);

            mysqli_close($db);
            $this->db = null;   
        } catch (Exception $e) {
            echo $e->errorMessage();
        }

    }
}

and i call it using this:

$data = $user->get_tutoriallist(); 
                        if (!empty($data)) {
                            foreach ($data as $row){    
                                echo "<tr>";    
                                echo"<td>".$row['category']."</td>";
                                echo"<td>".$row['title']."</td>";
                                echo"<td>".$row['detail']."</td>";
                                echo"<td>".$row['photo']."</td>";
                                echo"<td>".$row['video_link']."</td>";
                                echo"<td>".$row['date_post']."</td>";
                                echo"<td class='option'><center><a href ='#' class='edit'>Edit</a>
                                    &nbsp;<a href='#'>Delete</a></center></td>";                                    
                                echo "</tr>";
                            }
                        }else{
                                echo '<tr><td colspan="6"><center><h2>No entries</h2></center></td></tr>';
                        }

I'm not quite sure what is going on here:

        while($row = $result->fetch_assoc()){
            $count_row = $result->num_rows;
            if ($count_row == 1) {
            $dataArray[] = $row;
            }

But normally, you just iterate through the results and append them to an array:

        while($row = $result->fetch_assoc()){
            $dataArray[] = $row;
            }

Then your $datArray has all the rows in it.

This is because you are appending to the result array only when $current_row == 1.

Try changing your while loop like this:

while($row = $result->fetch_assoc()){
    $dataArray[] = $row;
}

Also, you are not closing the db connection correctly, you are mixing OOP style with procedural mysqli functions. This is how it should be:

$this->db->close();
$this->db = null;

Finally, you should return the data array after you closed the connection. If you returned the data array first and closed the connection after, that code wont get executed.

So your last three lines should look like this:

$this->db->close();
$this->db = null;
return $dataArray;