WHERE更新并重新进入WHERE id

view2.php is an extension or displaying the rest of my code in another file from the other file im targeting the certain id then update it from view2.php into update_info.php but ill get this error

Notice: Undefined variable: id in . . . .

but in my database it was updated just didnt display into my webpage to shorten it

from view2.php into update_info.php back to view2.php after update but ill get this error

Notice: Undefined variable: id in . . . .

view2.php

<?php
include 'dbconfig.php';
$id = $_GET['id'];
$sql = "SELECT * FROM info WHERE id = '$id'";
$result = mysql_query($sql);
$row = mysql_fetch_array($result);
?>

update_info.php

$sql = "SELECT id FROM info";
$result = mysql_query($sql);
$row = mysql_fetch_array($result);

"SOME CODES HERE"

Header("Location: view2.php?=".$row['id']);

You haven't set id parameter in your redirection part:

Header("Location: view2.php?id=".$row['id']);

instead of:

Header("Location: view2.php?=".$row['id']);

mysql_fetch_array returns an array so your id is probably undefined because row is an array. You should try row[0]['id'] if you want the first element and probably do some check to see if the result is not an empty variable from the db. Try var_dump(row) to see what you get from the database. Also you should use require_once for your dbconfig instead of include.