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);
?>
The MongoDB\Driver\Command class
(mongodb >=1.0.0)
简介
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.
类摘要
final
class MongoDB\Driver\Command
{
/* 方法 */
}示例
示例 #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;
}
?>以上示例会输出：
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)
}
目录
- MongoDB\Driver\Command::__construct — Create a new Command
add a note
User Contributed Notes 4 notes
tdrpic ¶
8 years ago
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.
532041020 at qq dot com ¶
7 years ago
Wrong:
$cmd = new \MongoDB\Driver\Command([
'aggregate' => 'collection',
'pipeline' => ['$group' => ['_id' => null, 'count' => ['$sum' => '$total']]]
]);
Right:
$cmd = new \MongoDB\Driver\Command([
'aggregate' => 'collection',
'pipeline' => [['$group' => ['_id' => null, 'count' => ['$sum' => '$total']]][
]);
The 'pipeline' lack of '[]'
deiva at qq dot com ¶
7 years ago
I try to use the driver 1.29 (https://pecl.php.net/package/mongodb/1.2.9) in PHP 5.7, as following codes:
$mongo = new \MongoDB\Driver\Manager('mongodb://localhost:27017');
$cmd = new \MongoDB\Driver\Command([
'aggregate' => 'collection',
'pipeline' => ['$group' => ['_id' => null, 'count' => ['$sum' => '$total']]]
]);
$rows = $mongo->executeCommand('database', $cmd);
foreach($rows as $r){
print_r($r);
}
it sometime saids:
Fatal error: Uncaught exception 'MongoDB\Driver\Exception\RuntimeException' with message ''pipeline' must be specified as an array'
sometime as :
Fatal error: Uncaught exception 'MongoDB\Driver\Exception\ConnectionTimeoutException' with message 'No suitable servers found (`serverSelectionTryOnce` set): [socket timeout calling ismaster on '127.0.0.1:27017']'
PS: other command can be executed normally.
