No matter if those numbers start at 300, or at 300000, you can always kinda guess, what’s the next one. Here we are, already facing one of the common problems when using „normal“ numbers. Sure, there are some cases where people want to define another starting point like at 5000, but. So basically this will be an incrementing number, which starts at like 1 and counting up. The first column inside that table, will usually display the unique identifier for that entity. So far this isn’t really exciting, i know, but what comes into your mind, when thinking about the first column? You got that usual screen with something like a table, which displays some data about the listed entities. So imagine having that graphical user interface, like most of the time, with some kind of list. The background story – PHP generate UUID’s Background story – PHP generate UUIDsīefore we actually start thinking about code, we could also start from a little different angle. So let’s get into the background story and later into how we can actually create/generate one. This doesn’t only apply for the developers side, customers and other involved parties actually want something else, too. Using a different approach than those normal „1, 2. It doesn’t matter if it’s stored in a good old MySQL Database, or in one of the document based alternatives. Many projects nowadays require a new way of generating that unique identifier for like your entities. There are different versions of UUIDs, but the main focus will lie on generating an UUID of the version 4. Those „special kind“ identifiers are – as the name obviously suggests – for uniquely identifying „things“. In this post i will partially dive into the thing called universally unique identifiers. I welcome you to todays post on „How to make PHP generate a UUID for you?“. You want to make PHP generate UUIDs for you!?
$time_hi_and_version = $time_hi_and_version > 4 $time_hi_and_version = hexdec($time_hi_and_version) * time_hi_and_version field to the 4-bit version number from * Set the four most significant bits (bits 12 through 15) of the $node = bin2hex(substr($randomString, 10, 6)) $clock_seq_hi_and_reserved = bin2hex(substr($randomString, 8, 2)) $time_hi_and_version = bin2hex(substr($randomString, 6, 2)) $time_mid = bin2hex(substr($randomString, 4, 2)) $time_low = bin2hex(substr($randomString, 0, 4)) $randomString = openssl_random_pseudo_bytes(16) My answer is based on comment uniqid user comment but it uses openssl_random_pseudo_bytes function to generate random string instead of reading from /dev/urandom function guid() With PHP 7, generating random byte sequences is even simpler using random_bytes(): function guidv4($data = null) The following approach generates 128 bits of random data using openssl_random_pseudo_bytes(), makes the permutations on the octets and then uses bin2hex() and vsprintf() to do the final formatting. clock_seq_hi_and_reserved (bit 6 & 7 of 9th octet)Īll of the other 122 bits should be sufficiently random.time_hi_and_version (bits 4-7 of 7th octet),.You should also use a better random number generator than mt_rand().Īccording to RFC 4122 - Section 4.4, you need to change these fields: Instead of breaking it down into individual fields, it's easier to generate a random block of data and change the individual byte positions. I was hoping someone with more knowledge than me in this area could lend me a hand and help me fix this function so it does adhere to that rule. This is where the functions fails as it doesn't adhere to that. This function generates a valid v4 UUID up until one area. My knowledge in hex, decimal, binary, PHP's bitwise operators and the like is nearly nonexistent. This is the closest I've been able to come. So I've been doing some digging around and I've been trying to piece together a function that generates a valid v4 UUID in PHP.