MongoDB PHP Limit not working - php

Question

I use this code in the MongoDB PHP driver to get all documents in the database
$result = $collection->find();
foreach ($result as $doc) {
print_r($doc);
}
However, when adding a limit to it, it doesn't work anymore: no documents get printed anymore:
$result = $collection->find()->limit(10);
foreach ($result as $doc) {
print_r($doc);
}
There are certainly enough documents in the database. I cannot figure out what the problem with this is.

Answer 1

I have fixed the problem by taking a look at the source of the beta version. The documentation only appeared to be for the legacy mongo extension and not the newer mongodb extension.
The error logs showed this: Call to undefined method MongoDB\\Driver\\Cursor::addOption(). I checked out the documentation and concluded the function should have worked because it said (PECL mongo >=0.9.0). Note the missing db after mongo.
I fixed it by doing:
$collection->find([], [ 'limit' => 2 ]);, providing an empty filters array and adding my options in another array afterwards.

Answer 2

I am trying to describe with example for new php mongodb driver. showing in example skip,limit,Fields slection
require 'vendor/autoload.php'; // include Composer's autoloader
$client = new MongoDB\Client("mongodb://localhost:27017");
// SELECT * FROM YOUR_TABLE_NAME ;
// db.YOUR_COLLECTION_NAME.find({});
$result = $clinet->YOUR_DB_NAME->YOUR_COLLECTION_NAME->find(array());
//SELECT * from YOUR_TABLE_NAME WHERE YOUR_COLUMN = "A"
// db.YOUR_COLLECTION_NAME.find({{ YOUR_FIELD: "A" }});
$result = $clinet->YOUR_DB_NAME->YOUR_COLLECTION_NAME->find(array('YOUR_FIELD'=>'A'));
//Return the Specified Fields and the _id Field Only
//SELECT _id, item,status YOUR_TABLE_NAME from inventory WHERE status = "A"
//db.YOUR_COLLECTION_NAME.find( { status: "A" }, { item: 1, status: 1 } )
$result = $clinet->YOUR_DB_NAME->YOUR_COLLECTION_NAME->find(array('status'=>'A'),array('projection' =>array('item'=>TRUE,'status' => TRUE)));
//Suppress _id Field
//SELECT item, status from YOUR_TABLE_NAME WHERE status = "A"
//db.YOUR_COLLECTION_NAME.find( { status: "A" }, { item: 1, status: 1, _id: 0 } )
$result = $clinet->YOUR_DB_NAME->YOUR_COLLECTION_NAME->find(array('status'=>'A'),array('projection' =>array('item'=>TRUE,'status' => TRUE,'_id'=>FALSE)));
//SELECT * FROM YOUR_TABLE_NAME LIMIT 10
//db.YOUR_COLLECTION_NAME.find({}).limit(10);
$result = $clinet->YOUR_DB_NAME->YOUR_COLLECTION_NAME->find(array(),array('limit'=>10));
//SELECT * FROM YOUR_TABLE_NAME LIMIT 5,10
//db.YOUR_COLLECTION_NAME.find({}).skip(5).limit(10)
$result = $clinet->YOUR_DB_NAME->YOUR_COLLECTION_NAME->find(array(),array('skip'=>5,'limit'=>10));
//Suppress _id Field
//SELECT item, status from YOUR_TABLE_NAME WHERE status = "A" LIMIT 5,10;
//db.YOUR_COLLECTION_NAME.find( { status: "A" }, { item: 1, status: 1, _id: 0 } ).skip(5).limit(10);
$result = $clinet->YOUR_DB_NAME->YOUR_COLLECTION_NAME->find(array('status'=>'A'),array('projection' =>array('item'=>TRUE,'status' => TRUE,'_id'=>FALSE),'skip'=>5,'limit'=>10));
foreach ($result as $entry){
echo "<pre>";
print_r($entry);
echo "</pre>";
}

Answer 3

As a solution to your above mentioned problem please try executing following code snippet.
$result = $collection->find();
$result->limit(10);
foreach ($result as $doc) {
print_r($doc);
}

Answer 4

I had the same issue. There are a lot of code examples using $result = $collection->find()->limit(10);
It turns out, that while this was totally valid for the original version of the MongoDB PHP driver, there is a new version of that very same driver. The original driver is now considered "The Legacy Driver".
Here is one example, how the "old" driver was supposed to be used:
<?php
$m = new MongoClient;
// Select 'demo' database and 'example' collection
$collection = $m->demo->example;
// Create the cursor
$cursor = $collection->find();
At this moment, although a cursor object had been created, the query had not yet executed (i.e. it was not sent to the server). The query would only be executed by starting iteration with foreach ( $cursor as $result ) or calling $cursor->rewind(). This gives you the chance to configure the cursor's query with sort(), limit(), and skip() before it is executed by the server:
// Add sort, and limit
$cursor->sort( [ 'name' => 1 ] )->limit( 40 )
In the new driver, as soon as you have a \MongoDB\Driver\Cursor object, it has already been processed by the server. Because sort (and limit and skip) parameters need to be sent to the server before the query is executed, you can not retroactively call them on an existing Cursor object.
This is the reason, why there is no limit() method anymore, as there used to be. Also, the accepted answer is correct. I want to give a more elaborate example:
$filter = [
'author' => 'rambo',
'views' => [
'$gte' => 100,
],
];
$options = [
/* Return the documents in descending order of searchPage */
'sort' => [
'searchPage' => -1
],
/* Limit to 2 */
'limit' => 2,
/* close the cursor after the first batch */
'singleBatch' => true,
];
$cursor = $collection->find($filter, $options);