扩展MySQLi类

class ExtendedMySQLi extends MySQLi {
    public function __construct($host, $username, $password, $database) {
        parent::__construct($host, $username, $password, $database);
    }

    public function getAll($tableName) {
        $sql = "SELECT * FROM $tableName";
        $result = $this->query($sql);
        $rows = array();
        while ($row = $result->fetch_assoc()) {
            $rows[] = $row;
        }
        return $rows;
    }
}

$db = new ExtendedMySQLi("localhost", "username", "password", "database");
$rows = $db->getAll("users");
foreach ($rows as $row) {
    echo $row["name"] . "<br>";
}