Can't get data from mongoDB

Question

I create function to get data from mongoDB by PHP code. But It seem not working well.

let's see my code

function updateperformancescore($timepf)
    {
        $mon = new Mongo('mongodb://127.0.0.1:27017');
        $dbs = $mon->selectDB('bitdindatabase');
        $col = $dbs->selectCollection('bd_performance_score');

        $query2 = array("user_ID"=>"999");
        echo "<br>query__".$query2["user_ID"];

        $data2 = $col->find($query2,true);
        echo "<br>count___".count($data2)."<br>";
        echo "check is_object--".is_object($data2)."<br>";
        //echo "--".$data2["user_ID"]."<br>";
        error_reporting(E_ALL ^ E_NOTICE);
        foreach ($data2 as $obj) 
            {
                echo "aaaa";

                $which = array("user_ID"=>$obj["user_ID"],"time"=>$obj["ps_avgtime"],"slug"=>$obj["lesson_slug"]);

                echo json_encode($which);
            }

and webpage show only

query_ 999 count __1 check is_object--1

but my data in mongo is

{ "_id" : ObjectId("501e768eefbdb8637e2b00c8"), "user_ID" : 999, "lesson_slug" : 999, "ps_avgtime" : 999 }
{ "_id" : ObjectId("501e7698efbdb8637e2b00c9"), "user_ID" : 999, "lesson_slug" : 998, "ps_avgtime" : 888 }
{ "_id" : ObjectId("501e76a1efbdb8637e2b00ca"), "user_ID" : 999, "lesson_slug" : 997, "ps_avgtime" : 777 }
{ "_id" : ObjectId("501e76a9efbdb8637e2b00cb"), "user_ID" : 999, "lesson_slug" : 996, "ps_avgtime" : 77 }
{ "_id" : ObjectId("501e76b6efbdb8637e2b00cc"), "user_ID" : 999, "lesson_slug" : 995, "ps_avgtime" : 555 }
{ "_id" : ObjectId("501e76c0efbdb8637e2b00cd"), "user_ID" : 999, "lesson_slug" : 994, "ps_avgtime" : 444 }
{ "_id" : ObjectId("501e76caefbdb8637e2b00ce"), "user_ID" : 999, "lesson_slug" : 993, "ps_avgtime" : 333 }
{ "_id" : ObjectId("501e76d3efbdb8637e2b00cf"), "user_ID" : 999, "lesson_slug" : 992, "ps_avgtime" : 222 }
{ "_id" : ObjectId("501e76dcefbdb8637e2b00d0"), "user_ID" : 999, "lesson_slug" : 991, "ps_avgtime" : 111 }
{ "_id" : ObjectId("501e76e6efbdb8637e2b00d1"), "user_ID" : 999, "lesson_slug" : 990, "ps_avgtime" : 1 }

Why it's not going into foreach ? And What's wrong with this code and How I get data correctly. help or guide me please :)

edit

I just error_log and It show

Fatal error: Uncaught exception 'MongoException' with message 'The MongoCursor object has not been correctly initialized by its constructor' in /var/www/web/sendanswer.php:92 Stack trace: #0 /var/www/web/sendanswer.php(92): MongoCursor->rewind() #1 /var/www/web/sendanswer.php(343): sendanswer->updateperformancescore(4.4269230365753) #2 {main} Next exception 'MongoException' with message 'The MongoCursor object has not been correctly initialized by its constructor' in /var/www/web/sendanswer.php:92 Stack trace: #0 /var/www/web/sendanswer.php(92): MongoCursor->rewind() #1 /var/www/web/sendanswer.php(343): sendanswer->updateperformancescore(4.4269230365753) #2 {main} thrown in /var/www/web/sendanswer.php on line 92

what does it mean ??

edit

That means "Probably your Mongo object is not connected to a database server."

Answer 1

What I see is an error in datatypes.

In database user_ID is an integer, in your PHP query, it is a string. Try:

$query2 = array("user_ID"=> 999);

instead of :

$query2 = array("user_ID"=>"999");

PHP may be easy on datatypes, but I am not sure about Mongodb and its PHP driver.

Also there is an incorrect parameter in your find statement. Remove the true as it should be an array of fields, not a bool

This code works correctly :

<?php

$mon = new Mongo('mongodb://127.0.0.1:27017');
$dbs = $mon->selectDB('my_db');
$col = $dbs->selectCollection('newColl');

$query2 = array("user_ID"=> 999);
echo "<br>query__".$query2["user_ID"];

$data2 = $col->find($query2);

error_reporting(E_ALL ^ E_NOTICE);
foreach ($data2 as $obj)
{

  $which = array("user_ID"=>$obj["user_ID"],
                 "time"=>$obj["ps_avgtime"],
                 "slug"=>$obj["lesson_slug"]);
  echo json_encode($which);
  echo PHP_EOL ;
}
?>

Output:

[......]$ php testmongo.php 
<br>query__999{"user_ID":999,"time":999,"slug":999}
{"user_ID":999,"time":999,"slug":999}
{"user_ID":999,"time":339,"slug":999}
{"user_ID":999,"time":339,"slug":5599}