我的插入不起作用，但我没有任何错误

Question

我的mysqli插入因某些原因不起作用，但我没有收到任何错误。

<?php

$con=mysqli_connect("localhost","root","","dice");
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

mysqli_query($con,"INSERT INTO `gamble` (thr,score,tstamp)
VALUES ('test123','test123','test123')");
echo "New record has id: " . mysqli_insert_id($con);

mysqli_close($con);

 ?>

我真的不知道自己做错了什么。提前谢谢。