The MongoDB\Driver\Command class
(mongodb >=1.0.0)
はじめに
The MongoDB\Driver\Command class is a value object that represents a database command.
To provide Command Helpers
the MongoDB\Driver\Command object should be composed.
クラス概要
例
例1 Composing MongoDB\Driver\Command to provide a helper to create 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;
}
?>
上の例の出力は以下となります。
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) }
目次
- MongoDB\Driver\Command::__construct — Create a new Command
+add a note
User Contributed Notes 2 notes
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);
?>
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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