La classe MongoDB\Driver\Command

(mongodb >=1.0.0)

Introduction

La classe MongoDB\Driver\Command est un objet de valeur qui représente une commande de base de données.

Pour fournir des Command Helpers, l'objet MongoDB\Driver\Command doit être composé.

Synopsis de la classe

final class MongoDB\Driver\Command {

/* Méthodes */

final public __construct(array|object $document, ?array $commandOptions = null)

}

Exemples

Exemple #1 Composé MongoDB\Driver\Command pour fournir un assistant pour créer des collections

<?php
class CreateCollection {
    protected $cmd = array();

    function __construct($collectionName) {
        $this->cmd["create"] = (string) $collectionName;
    }
    function setCappedCollection($maxBytes, $maxDocuments = false) {
        $this->cmd["capped"] = true;
        $this->cmd["size"]   = (int) $maxBytes;

        if ($maxDocuments) {
            $this->cmd["max"] = (int) $maxDocuments;
        }
    }
    function usePowerOf2Sizes($bool) {
        if ($bool) {
            $this->cmd["flags"] = 1;
        } else {
            $this->cmd["flags"] = 0;
        }
    }
    function setFlags($flags) {
        $this->cmd["flags"] = (int) $flags;
    }
    function getCommand() {
        return new MongoDB\Driver\Command($this->cmd);
    }
    function getCollectionName() {
        return $this->cmd["create"];
    }
}


$manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");

$createCollection = new CreateCollection("cappedCollection");
$createCollection->setCappedCollection(64 * 1024);

try {
    $command = $createCollection->getCommand();
    $cursor = $manager->executeCommand("databaseName", $command);
    $response = $cursor->toArray()[0];
    var_dump($response);

    $collstats = ["collstats" => $createCollection->getCollectionName()];
    $cursor = $manager->executeCommand("databaseName", new MongoDB\Driver\Command($collstats));
    $response = $cursor->toArray()[0];
    var_dump($response);
} catch(MongoDB\Driver\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

?>

L'exemple ci-dessus va afficher :

object(MongoDB\Driver\Command)#3 (1) {
  ["command"]=>
  array(3) {
    ["create"]=>
    string(16) "cappedCollection"
    ["capped"]=>
    bool(true)
    ["size"]=>
    int(65536)
  }
}
array(1) {
  ["ok"]=>
  float(1)
}
array(16) {
  ["ns"]=>
  string(29) "databaseName.cappedCollection"
  ["count"]=>
  int(0)
  ["size"]=>
  int(0)
  ["numExtents"]=>
  int(1)
  ["storageSize"]=>
  int(65536)
  ["nindexes"]=>
  int(1)
  ["lastExtentSize"]=>
  float(65536)
  ["paddingFactor"]=>
  float(1)
  ["paddingFactorNote"]=>
  string(101) "paddingFactor is unused and unmaintained in 2.8. It remains hard coded to 1.0 for compatibility only."
  ["userFlags"]=>
  int(0)
  ["capped"]=>
  bool(true)
  ["max"]=>
  int(9223372036854775807)
  ["maxSize"]=>
  int(65536)
  ["totalIndexSize"]=>
  int(8176)
  ["indexSizes"]=>
  object(stdClass)#4 (1) {
    ["_id_"]=>
    int(8176)
  }
  ["ok"]=>
  float(1)
}

Sommaire

MongoDB\Driver\Command::__construct — Crée une nouvelle commande

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User Contributed Notes 2 notes

down

tdrpic ¶

8 years ago

In case you're wondering how to perform a 'distinct' query:

<?php

// Sample MongoDB command:
// db.product.distinct("scent", {"prodCat": "10 oz can"})

$manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");

$query = ['prodCat' => '10 oz can']; // your typical MongoDB query
$cmd = new MongoDB\Driver\Command([
    // build the 'distinct' command
    'distinct' => 'product', // specify the collection name
    'key' => 'scent', // specify the field for which we want to get the distinct values
    'query' => $query // criteria to filter documents
]);
$cursor = $manager->executeCommand('catalog', $cmd); // retrieve the results
$scents = current($cursor->toArray())->values; // get the distinct values as an array

var_dump($scents);

?>

down

jonny dot b dot 112 at gmail dot com ¶

6 years ago

0) Read the official MongoDB documentation for understand what db commands you can use and what parameters they requires - https://docs.mongodb.com/manual/reference/command/

1) Wrong:
$cmd = new \MongoDB\Driver\Command([
    'aggregate' => 'collection',
    'pipeline' => ['$group' => ['_id' => null, 'count' => ['$sum' => '$total']]]
]);
because pipeline is array of objects in json words (index array of associative arrays in php words) - pipeline: [ {<stage>}, ... ]
What does it mean? It means that  'pipeline' must be like this:
[
    ['$group' => ['_id' => null, 'count' => ['$sum' => '$total']]],    // this is {<stage>}
    ['$match' => [...]],    // and this
    ...
    [...]    // and all of that
]
Just see https://docs.mongodb.com/manual/reference/operator/aggregation-pipeline/

2) The first pair in associative array for __construct's argument $document (if it is an array) must be a command name (e. g. 'count' => 'collectionName' or 'findAndModify' => 'collectionName'). I found this out experimentally, but you can examine source code  https://github.com/mongodb/mongo-php-driver/blob/master/src/MongoDB/Command.c for understand why it happens.

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