PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Implementing Bookmark Storage and Retrieval
601
Listing 27.24
Continued
}
// get the bookmarks this user has saved
if ($url_array = get_user_urls($valid_user)) {
display_user_urls($url_array);
}
display_user_menu();
do_html_footer();
?>
You begin this script by performing the usual validations.When you know that the user
has selected some bookmarks for deletion, you delete them in the following loop:
foreach($del_me as $url) {
if (delete_bm($valid_user, $url)) {
echo 'Deleted '.htmlspecialchars($url).'.';
} else {
echo 'Could not delete '.htmlspecialchars($url).'.';
}
}
As you can see, the delete_bm() function does the actual work of deleting the bookmark
from the database.This function is shown in Listing 27.25.
Listing 27.25 delete_bm()Function in url_fns.php—This Function Deletes a
Single Bookmark from a User’s List
function delete_bm($user, $url) {
// delete one URL from the database
$conn = db_connect();
// delete the bookmark
if (!$conn->query("delete from bookmark where
username='".$user."' and bm_url='".$url."'")) {
throw new Exception('Bookmark could not be deleted');
}
return true;
}
As you can see, delete_bm() is also a pretty simple function. It attempts to delete the
bookmark for a particular user from the database. Note that you want to remove a particular
username-bookmark pair in this case. Other users might still have this URL
bookmarked.
Some sample output from running the deletion script on the system is shown in
Figure 27.10.