php - 使用Php mysql查询不从php类获取数据，尽管有数据

Question

class book {

function __construct() {
$conn = mysql_connect('localhost', 'root', '') or die('can nit connect to DB');
mysql_select_db('atomic_project', $conn) or die('can not connect to db');
}

public function listView() {
    $allData = array();
    $query = "SELECT * FROM `book`";
    $result = mysql_query($query);
    while ($row = mysql_fetch_assoc($result)) {
        print_r($row);
        $allData [] = $row;
    }
    return $allData;
}

}

我的索引页

    $listViewObj = new book();
    $allData = $listViewObj->listView();

    echo "<pre>";
    print_r($allData);
    echo "<pre>";

这是我的代码和表格 here is my table data ，我可以将数据插入表中，但没有找到行 我不明白为什么没有显示数据，请帮助我

Answer 1

    <?php
class book {

public function listView() {
    $conn = mysql_connect('localhost', 'root', '') or die('can nit connect to DB');
    mysql_select_db('atomic_project', $conn) or die('can not connect to db');

    $allData = array();
    $query = "SELECT * FROM `book`";
    $result = mysql_query($query);
    while ($row = mysql_fetch_assoc($result)) {
        //echo "<pre>";
        //print_r($row);
        $allData [] = $row;
    }
   return $allData;
}
}
book::listView(); //scope resolution operator 
?>

或通过对象调用函数

$obj = new book();
$obj->listView();