这个怎么改才对？？？

Question

<?phpheader("Content-type:text/html;charset=utf-8");if ($con = mysqli_connect('localhost','root','838814993')){  echo"链接成功\n";}else{  echo"连接失败\n";}$query = mysqli_query($con,'select * from category');mysqli_fetch_row($query);

Answer 1

看提示，$data,$dbc变量都没有声明,