How can I keep the URL id on submit? - php

Question

When I click submit, the data is submitted to the database but the URL id of the book disappears to ----book.php
I want the URL to go back to the id of the page e.g. ----book.php?id=3
Is it possible to keep the first line as action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" and add the value="<?php echo $book_id ?>"?
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
<input type="hidden" value="<?php echo $book_id ?>" name="book_id" />
<p>Author: <input type="text" value="<?php echo $_SESSION['author']; ?>" name="author" id="author" readonly /></p>
<p>Summary: <input type="text" name="summary" value="<?php echo $summary;?>" /></p>
<p><input type="submit" name="submit" value="Submit" /></p>
<input type="hidden" name="submitted" value="TRUE" />
</form>
PHP code:
if (isset($_GET['id'])) {
$book_id = $_GET['id'];
}

Answer 1

Please try this code:
// save values in DB
header('Location: book.php?id=' . $book_id);
exit;

Answer 2

It is because $_SERVER["PHP_SELF"] contains only URL . It does not contain get queries . To solve the problem leave your action empty
e.g
<form method="post" action="">.....

Answer 3

You send a POST form but are trying to retrieve a GET value. Additinally, the parameter is named book_id, not id.
Use $book_id = $_POST['book_id'];
if (isset($_GET['id'])) { also won't work, for the same reasons.

Answer 4

There is no name with "id"
If you want to get the book id:
if (isset($_POST['book_id'])) {
$book_id = $_POST['book_id'];
}
OR modify the HTML like this:
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
<input type="hidden" value="<?php echo $book_id ?>" name="id" />
<p>Author: <input type="text" value="<?php echo $_SESSION['author']; ?>" name="author" id="author" readonly />
</p>
<p>Summary: <input type="text" name="summary" value="<?php echo $summary;?>" /></p>
<p><input type="submit" name="submit" value="Submit" /></p>
<input type="hidden" name="submitted" value="TRUE" />
</form>
On the other hand, if you have problems with POST, just modify the first line of HTML for this one:
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]) . "?id=" . echo $book_id; ?>">

Answer 5

You can use anyone of these:
PHP_SELF returns just URL. Use REQUEST_URI that returns URL with query string:
<form method="post" action="<?php echo htmlspecialchars($_SERVER["REQUEST_URI"]);?>">
[you can also omit action values - that will have same behavior]
or if you want just id, then use:
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]) . "?id=" . $_GET['id'];?>">
Note: Use validation wherever necessary. I just gave you an idea.