#uniqueid

[freewwwcom]

Generate Unique UUIDs Easily 🔑

Need unique identifiers for your apps or databases? The UUID Generator gives you secure, random UUIDs instantly perfect for developers and tech enthusiasts.

🔗https://www.freewww.com/apps/uuid/

[vaartharavi]

Breaking News -ID No: Unique ID number for tenant farmers soon!

Breaking News -ID No : త్వరలో కౌలు రైతులకు యూనిక్ ఐడీ నంబర్!

ఈ నిర్ణయం ద్వారా కౌలు రైతులకు మరింత భరోసా కలుగుతుందని నిపుణులు అభిప్రాయపడుతున్నారు. ఇప్పటివరకు పంట నష్టాలు లేదా ప్రభుత్వ

[webnameseller]

Brand Your Unique Online Identity

qokaz.com is short, catchy, and perfect for startups, tech ventures, or branding projects. https://www.godaddy.com/en-uk/domainsearch/find?domainToCheck=qokaz.com

[sarkariyojnaaorg]

UDID Project | Unifying Databases for India's Development

UDID Project is a unique identification project for domestic animals to enhance disease control and increase efficiency in livestock managem

[thecodeslayer-blog-blog]

Using the MongoId as the Created Date

On my current project, we have been making improvements to our mongo database by removing unneeded indexes. We store a created date in one of our collections and we were sorting and grabbing documents using that date. However that isn't really needed in this situation since the way Mongo's unique id is created. So first lets go into how MongoId's are created, every MongoId has 4 things:

A 4-byte UNIX timestamp

Machine-Id

Process Id

An increment value 

All of those values are compiled into one string to make it a unique id. That string is created into an object, which becomes the id. Check out this link for more info: MongoId Documentation

We needed the created date for two reasons:

To sort by most recent

To get documents that were created since a specified date

The solution for the first one is easy. To sort by created date, assuming that the date hasn't changed since the actual creation of that document, you basically just sort by the '_id' by using $cursor->sort(array( '_id' : '1' )) [ASC] or $cursor->sort(array( '_id' : '-1' )) [DESC]. This works since the first four bytes in the id are a UNIX timestamp.

The solution for the second one was a little more complex. Basically, you pull a certain amount of documents from the collection and then filter out the documents that are older then the specified date and grab more documents if necessary. Here is an example of the code for this:

function getDocuments($name, $params = array()){ global $coll; //this is the condition in the query    $conditions['name'] = $name; //limit can be anything you want $limit = 10;    $offset = isset($params['offset']) ? $params['offset'] : 0; //order them by the created date    $order = array('_id' => '-1'); //run the query (This may differ)    $documents = $coll->find($conditions)->sort($order)->limit($limit)->skip->($offset); //convert mongo cursor object to an array - not required but remember but to make the required changes this function $documents = iterator_to_array($documents);    //add a fail safe if(empty($documents) || count($documents) == 0){   return array(); } //prepare values for passing into array_filter function    $this->since = $params['since'];    $_this = $this; //filter the documents to get rid of ones that a before the since date $documents =  array_filter($documents, function($doc) use ($_this) {      $since = $_this->since; if (isset($since) && !is_null($since)){ if($since->sec < $doc['created']->sec){ return true; }else{ return false; } }else{ return false; } }); //If the number of documents returned equal the limit then re-iterate through this function to process more. WARNING: This is possibly and endless loop if(count($documents) == $limit){ $params['offset'] = $offset + $limit; //potential infinite loop $more = $this->getDocuments($name, $params); foreach($more as $doc){ $documents[] = $doc; } } //return the documents return $documents; }