PHP - How To Generate Unique Ids That Only Contains Alphanumeric Characters

I am looking to generate a random number for every user contribution as a title of the contribution.

I could simply check the database each time with a query and generate a number which does not equal to any of the entries of the database. But I imagine this as inefficient and it could become slow if the database is big in my opinion. Also I'd have to contain all the numbers of the database somewhere to manage the "not equals to", in an array or something similar but that can end up as a giant one.

Excuse the layman's speech I am new to this.

Any suggestions how this can be solved efficiently without straining the resources too much? You can explain it linguistically and do not have to provide me any scripts, I will figure it out.

hi!, is it possible to use rand() to generate unique number that will be saved in a database as a primary key? Since i dont want to have numbers like 00001 incrementing on the table. They dont look like real account numbers... i need something like 45642  or 95452 and the like.

thanks in advance.

I'm not sure I'm in the right place, but I'm looking to create a unique URL that links to the same page every time I send an email after a form is submitted on my website and have it expire after 15 days.  After expiring, the link would redirect to a default page.  I'm still a beginner and realize this is probably going to be a tough task, but any resources or direction provided would be much appreciated.

Thanks for the help in advance!

I have a mysql table which will store users email addresses (each is unique and is the primary field) and a timestamp. 
I have added another column called `'unique_code' (varchar(64), utf8_unicode_ci)`.

What I would very much appreciate assistance with is;

a) Generating a 5 digit alphanumeric code, ie: 5ABH6 
b) Check all rows the 'unique_code' column to ensure it is unique, otherwise re-generate and check again 
c) Insert the uniquely generated 5 digit alphanumeric code into `'unique_code'` column, corresponding to the email address just entered. 
d) display the code on screen.

What code must I put and where?


**My current php is as follows:**

Code: [Select]
    require "includes/connect.php";
   
    $msg = '';
   
    if($_POST['email']){
   
    // Requested with AJAX:
    $ajax = ($_SERVER['HTTP_X_REQUESTED_WITH']  == 'XMLHttpRequest');
   
    try{
    if(!filter_input(INPUT_POST,'email',FILTER_VALIDATE_EMAIL)){
    throw new Exception('Invalid Email!');
    }
   
    $mysqli->query("INSERT INTO coming_soon_emails
    SET email='".$mysqli->real_escape_string($_POST['email'])."'");
   
    if($mysqli->affected_rows != 1){
    throw new Exception('You are already on the notification list.');
    }
   
    if($ajax){
    die('{"status":1}');
    }
   
    $msg = "Thank you!";
   
    }
    catch (Exception $e){
   
    if($ajax){
    die(json_encode(array('error'=>$e->getMessage())));
    }
   
    $msg = $e->getMessage();
    }
    }

When I say something must be "alphanumeric", what do YOU define that as being?

To me, it means ONLY Upper-Case Letters, Lower-Case Letters, and Numbers (i.e. A-Z, a-z, 0-9).


Debbie

I have a user input string via GET variable that I want to always make sure falls within the constraints of type of variable its set for, which is a md5 hash.
So I want to put together using preg_match or something using a regex construct (even though I suck with regex) to verify that all the characters in the string are valid characters for a md5 hash, where if its not then I want to kick back an error. The idea of making something like that isnt the issue for me so much as not knowing whether or not an md5 has is strictly alphanumeric or if it can possibly even if one in a million chance have something else from an underscore to a exclamation point or other characters. Ive tried to find out searching google and other sites for an answer but my search terms I guess are way to open to find something distinctly close to what I am looking for answer wise, so I figured I'd give you guys a shot see if anyone knows.

I am working on taking out the Deprecated functions from my site so while replacing ereg with preg_match I get the below error. Per a message I found on the internet it says to replace ereg with preg_match and everything should work. Can anyone assist me with fixing this error?

Error: Warning: preg_match() [function.preg-match]: Delimiter must not be alphanumeric or backslash

Part where error is contained

if (preg_match('enum.(.*).', $row['Type'], $match)) {
    $opts = explode(',', $match[1]);
    foreach ($opts as $item)
        $finalResult[] = substr($item, 1, strlen($item)-2);
}


Full Function

function getEnumOptions($table, $field) {
   global $db;
   
   $finalResult = array();

   if (strlen(trim($table)) < 1)
    return false;
   
   $query  = "show columns from " . $db['tickets_slave']->escapeSimple($table);
   $res =& $db['tickets']->query($query);
   if (PEAR::isError($res)) {
throw new TixException($_SERVER['SCRIPT_NAME'] . ":", TixExceptionCodes::UNKNOWN_ERROR);
   } else {
try {
while ($res->fetchInto($row)) {
        if ($field != $row["Field"]) {
        
       } else {         
        //check if enum type
        if (preg_match('enum.(.*).', $row['Type'], $match)) {
            $opts = explode(',', $match[1]);
            foreach ($opts as $item)
                $finalResult[] = substr($item, 1, strlen($item)-2);
        }
       }
}
} catch (TixException $ex) {
throw new TixException($_SERVER['SCRIPT_NAME'] . ":", TixExceptionCodes::UNKNOWN_ERROR);
}
   }
   return $finalResult;
}

Jelly Bellys. So there are "recipes" of ones you can eat at the same time. The most well-known one is probably mixing a couple peanut butter jelly beans with a couple grapes. I have to say it's pretty good because they actually do taste like peanut butter and grapes, but I have one issue: the peanut butter flavor is too weak compared to the grape. Instead of a 1-1 ratio it takes more like 3-1.

Weird thing, this has got to be the most famous recipe so why isn't it listed on their site? I see candy apple, tiramisu, and lemon meringue pie, but nothing about peanut butter and jelly sandwiches. Are they just not popular anymore? Personally I prefer peanut butter and chocolate (Nutella, specifically) but whatever. Which can't be that weird because Reese's is popular... Mind you peanut butter + Nutella sandwiches don't really taste like Reese's candies, but that could just be because of the type of chocolate. Like they use milk or dark chocolate while Nutella is based on hazelnut.

Which reminds me, I have a jar of it in the cupboard, but it's been so long since I've used it that it might have turned into an oily mess by now. I know it's just the various oils and such separating but it looks like someone poured a teaspoon or two of water right into it and that just kinda puts me off the whole thing. Same for peanut butter for that matter except the "water" isn't clear. Dirty water. And mixing everything back together isn't so bad but it gets the knife dirty on the handle, which really bothers me because then my fingers get dirty and I have to stop what I'm doing and go wash my hands. I already do that enough each day, I don't want to make more reasons for me to do so.

But beyond the oily mess there's also stuff getting stale. Stale Nutella is a pain because it's stiff and hard to deal with, and the kind of bread I like most is very soft and easily rips apart so spreading it on can be a real labor. Best method I've found is to spread a little bit on at a time but it takes so long to cover the whole face. Fine, it's a good sandwich, but in that same time I could have done something else. Maybe there's something in the freezer I could quickly heat up, or maybe there's some leftovers in the fridge I could eat. And if not there's pretty good odds that I need to go to the grocery store anyways.

Ah, sorry. Forgot why I'm here.

This topic has been moved to MySQL Help.

http://www.phpfreaks.com/forums/index.php?topic=358112.0

I need to create a SEO friendly string only from alphanumeric and characters of my native language. It is sinhala.

My expected string should be something like this:

$myString = "this-is-a-දහසක්-බාධක-දුක්-කම්කටොලු-මැදින්-ලෝකය-දිනන්නට-වෙර-දරන";

I am using a function to create the string like this. And that function is as follow:

function seoUrl($string) {
    //Lower case everything
    $string = strtolower($string);
    //Make alphanumeric (removes all other characters)
    $string = preg_replace("/[^a-z0-9_\s-]/", "", $string);
    //Clean up multiple dashes or whitespaces
    $string = preg_replace("/[\s-]+/", " ", $string);
    //Convert whitespaces and underscore to dash
    $string = preg_replace("/[\s_]/", "-", $string);
    return $string;
}

This function only works for English characters and output of above string as below:

$title = seoUrl("this-is-a-දහසක්-බාධක-දුක්-කම්කටොලු-මැදින්-ලෝකය-දිනන්නට-වෙර-දරන");
echo $title; // this-is-a-

I modified this function using `mb_ereg_replace` as below:
 

function seoUrl($string) {
    //Lower case everything
    //$string = strtolower($string);
    //Make alphanumeric (removes all other characters)
    $string = mb_ereg_replace("/[^a-z0-9_\s-]/", "", $string);
    //Clean up multiple dashes or whitespaces
    $string = mb_ereg_replace("/[\s-]+/", " ", $string);
    //Convert whitespaces and underscore to dash
    $string = mb_ereg_replace("/[\s_]/", "-", $string);
    return $string;
}

But is not working for me.

Can anybody tell me how to modify above function to get all my characters (including my native language characters)

Hope somebody may help me out. Thank you.

Edited January 28, 2019 by thara

This topic has been moved to PHP Regex.

http://www.phpfreaks.com/forums/index.php?topic=347719.0

Can this be done with php?
aaa
aab
aac
...
zzz

Hi guys, so i have this file upload script. When i upload a file it gets stored in /uploads and keeps the same file name. So if i upload a file "test.exe" the file will be available at uploads/test.exe What i want is that it generates a new file name like: "9daln292os.exe" so upload/9daln292os.exe   This is my code:

<?php

// Where the file is going to be placed
$target_path = "uploads/";

/* Add the original filename to our target path.
Result is "uploads/filename.extension" */
$target_path = $target_path . basename( $_FILES['uploadedfile']['name']);
$_FILES['uploadedfile']['tmp_name'];

?>


<?php


$file_type = $_FILES['userfile']['type'];
$file_name = $_FILES['userfile']['name'];
$file_ext = strtolower(substr($file_name,strrpos($file_name,".")));

if (!in_array($file_type, $FILE_MIMES) && !in_array($file_ext, $FILE_EXTS) )
$message = "Sorry, $file_name($file_type) is not allowed to be uploaded.";
else
$message = do_upload_function_here($upload_path_here, $upload_ur_upload_url_herel);
?>
<?php



$target_path = "uploads/";

$target_path = $target_path . basename( $_FILES['uploadedfile']['name']);

if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
echo "The file ". basename( $_FILES['uploadedfile']['name']).
" has been uploaded. Here is the link to your file: <a href=uploads/". basename( $_FILES['uploadedfile']['name']). ">". basename( $_FILES['uploadedfile']['name'])."</a>";

} else{
echo "There was an error uploading the file, please try again!";
}

?>

I don't know any basic php i really need someone to give me the code ready please. Thanks much appreciated.
Edited by darox, 21 July 2014 - 01:07 PM.

Hi, can someone help me to understand this? What i want to do is to write some information in a form and after i submit the form that data will be in a new php page.

Thanks in advance

<?php
if(isset($_POST['submit'])){

	//collect form data
	$location = $_POST['location'];
	$ID = $_POST['ID'];
        $section = $_POST['section'];

	//check name is set
	if($location ==''){
		$error[] = 'Name is required';
	}

    //if no errors carry on
    if(!isset($error)){

		# Title of the CSV
		$Content = "location, ID, section\n";

		//set the data of the CSV
		$Content .= "$location, $ID, $section\n";

    # set the file name and create CSV file
    $my_file = ("$location$ID$section.cvs");
    $handle = fopen("$my_file", "w") or die('Cannot open file:  '.$my_file);
    header('Content-Type: application/csv'); 
    header('Content-Disposition: attachment; filename="' . $FileName . '"'); 
    echo $Content;
    exit();
	}
}

//if their are errors display them
if(isset($error)){
	foreach($error as $error){
		echo "<p style='color:#ff0000'>$error</p>";
	}
}
?> 

<form action='' method='post'>
<p><label>Location:</label><br><input type='text' name='location' value=''></p> 
<p><label>ID:</label><br><input type='text' name='ID' value=''></p> 
<p><label>Section:</label><br><input type='text' name='section' value=''></p>
<p><input type='submit' name='submit' value='Submit'></p> 
</form>

I have wrote a .php file which is a form with 3 different fields, in these fields I want to write entries which lateron will be submitted into a .csv generating a csv file on my server with the name of the entries.   The issue is that the file is not being generated on my server. With the current code the entries are being recognized and being placed in the filename of the csv.   The point is not to make it downloadable sinds I want to have it on my webserver and keep editing information in it.   My code is top of this post.   My .php file replies that: Cannot open file: BOD10Buffer.csv   Pardon my sloppy code everyone, I am not really a person that codes but this "form" may save me a lot of time in the longrun, just difficult and I am asking for help on this. Is there anyone that may be kind enough to help me? and as to what I might be doing wrong?   All help is much appreciated!