Add a number after a string, if it already exists - php

Question

I'm working on a script that checks if the url already exists in the database, and if yes adds an additional -1 or -2 etc etc at the end. I found this script
But it 'd need to to check it again after adding-1. Since it may be already existing. How can I do that? I tired i this way
$query = mysql_query("SELECT * FROM posts WHERE url='$url'");
while ( $query ) {
$result = mysql_fetch_assoc($query);
$url = $result['url'];
$urlnew = $result['url'];
$oldurl = $url;
$first = 1;
$separator = '-';
while ( $urlnew == $url ) {
$url = preg_match('/(.+)'.$separator.'([0-9]+)$/', $urlnew, $match);
$urlnew = isset($match[2]) ? $match[1].$separator.($match[2] + 1) : $url.$separator.$first;
$first++;
}
$url = $urlnew;
}
The new code above works just fine. But it checks only once. How can I make it to check untill it dose not exists in the DB?
tried adding a new sql query at the bottom after $url -$urlnew but it only breaks the function.
EDIT
Here's the correct script :D
$query = mysql_query("SELECT * FROM posts WHERE url LIKE '%".$url."%'");
if ( $query ) {
while ( $result = mysql_fetch_assoc($query) ) {
$url = $result['url'];
$urlnew = $result['url'];
$first = 1;
$separator = '-';
while ( $urlnew == $url ) {
preg_match('/(.+)'.$separator.'([0-9]+)$/', $urlnew, $match);
$urlnew = isset($match[2]) ? $match[1].$separator.($match[2] + 1) :$url.$separator.$first;
$first++;
}
}
}
$url = $urlnew;

Answer 1

Your code is likely vulnerable to SQL Injection. You should consider using PDO or MySQLi instead.
Here's an example of how you could do so:
$url = 'www.example.com';
$i = 0;
$max_duplicates = 100;
$query = $pdo->prepare('SELECT COUNT(id) count FROM urls WHERE url=?');
while ($i++ < $max_duplicates) {
$result = $query->execute($url);
if (!$result->fetch(PDO::FETCH_OBJ)->count)
break;
if ($i == 1) {
$url = $url . '-1';
} else {
$n = $i > 10 ? 2 : 1;
$url = substr($url, -$n) . $i;
}
}

Answer 2

Here's what I used for my needs
function checkLink($link, $counter=1){
global $connect;
$newLink = $link;
do{
$checkLink = mysqli_query($connect, "SELECT id FROM table WHERE link = '$newLink'");
if(mysqli_num_rows($checkLink) > 0){
$newLink = $link.'-'.$counter;
$counter++;
} else {
break;
}
} while(1);
return $newLink;
}
$link = 'www.example.com';
$uniquelink = checkLink($link);