检索数据库值应一一存储在文本文件中

Question

我通过php文件从数据库中检索了最后10个值，因为我试图将这10个值一个接一个地传递到文本文件中，但是这里的问题是只有一个最后一个值传递到了文本文件中。      如果我在终端中编译该特定php文件，则显示最后10个值，但未复制到文本文件中，仅复制一个值。

$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT pass FROM milestones ORDER BY id DESC LIMIT 10";
 $passres = $conn->query($sql);

  if ($passres->num_rows > 0) {
  // output data of each row
  while($row = $passres->fetch_assoc()) {
  //    echo "pass: " . $row["pass"]. "";
   $accessword= $row["pass"];
    echo $accessword;
     //exec ('php create_lic.php', $accessword); 
     file_put_contents ('test.txt', $accessword);
      //echo stream_copy_to_stream($accessword) . " bytes copied to              test.txt\n";   
         }
         } 
         else {
           echo "0 results";
              }
           $conn->close();
            ?> 
           I expect what are all the values displaying in the terminal it should be copy into the text file