我希望从以值形式存储的数据库中获取数据。因为当我返回值时，它会显示我不需要的值。
所以当我回显国家时，它会显示我要查找的ax，并且岛的值存储在数据库中。

<form action="reg_page.php" id="regform">
    Username:<input type="text" name="username">
      Password:<input type="text" name="password">
    Confirm Password:<input type="text" name="conpassword">
    Country:    
   <select id="city" name="city" required>
      <option value="AX">Aland Islands</option>

    <input type="submit">
  </form>

include("db.php"); // include the connection object from the DBConnection.php 
if ($_SERVER['REQUEST_METHOD'] == 'POST') { 
    $inUsername = $_POST["username"]; 
    $inPassword = $_POST["password"]; 
    $encryptPassword = password_hash($inPassword, PASSWORD_DEFAULT); 
    $inCountry = $_POST["city"]; 
    $stmt = $db->prepare("INSERT INTO users(username,password,center) VALUES(?, ?,?)"); 
    $stmt->bind_param("sss", $inUsername , $encryptPassword, $inCountry); 
    $stmt->execute(); 
    $result = $stmt->affected_rows; 
    $stmt -> close(); 
    $db -> close(); 
    if($result > 0)