如何在neo4jphp中实现标签的自动递增id属性？

Question

I have to create schema such that there will be property "id" for label "City". I have to make autoincrement value of "id" on every node I create of label type "City". I am using PHP library of neo4j: neo4jphp

I have seen this task Auto Increment in Neo4j but it is not having way given to do by php or specific strategy.

Answer 1

您可以使用Java（或其他JVM语言）编写不受管理的扩展 ，该扩展使用TransactionEventHandler来管理计数器并将其部署到Neo4j服务器。

Answer 2

This isn't technically what you asked for (since it isn't an auto-increment or numeric) since neo4j doesn't have an auto-increment... but this is how I solved the same problem by generating a randomized string as an ID

change $length if you want a different default length, $tries is just used to prevent an infinite loop... (this function tries to create a unique ID of 5 length 3 times, then tries to create 6 long id etc...

function makeNewID($client, $length = 5, $trys = 0)
   {
      //chars to pick from
      $charlist = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
      $strlen = strlen($charlist)-1;

      //alpha numeric generated in this for statement
      for ($newID = '', $i = 0; $i < $length; $newID .= $charlist[mt_rand(0, $strlen)], ++$i);
      //query the database to see if the 'new id exists'
      $query = new Everyman\Neo4j\Cypher\Query($client, 'MATCH (n{id:"'.$newID.'"}) RETURN n.id LIMIT 1');
      $result = $query->getResultSet();
      if(!empty($result[0]['x']->getProperty('id')))
      {
        $trys++;
        if($trys >= 3){$length++; $trys = 0;}
        $newID = makeNewID($Neo, $length, $trys);
      }
      return $newID;
   }

PS. I removed the abstraction layer in my code and replaced it with the actual neo4jphp lib's code, but i haven't tested it.