[edit] Last updated: Fri, 07 Jun 2013

MongoDB::command

(PECL mongo >=0.9.2)

MongoDB::command — Execute a database command

Описание

public array MongoDB::command ( array $command [, array $options = array() ] )

Almost everything that is not a CRUD operation can be done with a database command. Need to know the database version? There's a command for that. Need to do aggregation? There's a command for that. Need to turn up logging? You get the idea.

This method is identical to:


<?php

public function command($data) {
    return $this->selectCollection('$cmd')->findOne($data);
}

?>

Список параметров

command

The query to send.

options

This parameter is an associative array of the form array("optionname" => <boolean>, ...). Currently supported options are:

"timeout"
Целое значение, по умолчанию равно MongoCursor::$timeout. Если установлен флаг "safe", то значение обозначает количество миллисекунд, в течение которого клиент будет ожидать ответа от базы данных. Если база данных не ответит в течение указанного периода, то будет брошено исключение MongoCursorTimeoutException.

Список изменений

Версия	Описание
1.2.0	Added options parameter with a single option: "timeout".

Возвращаемые значения

Returns database response. Every database response is always maximum one document, which means that the result of a database command can never exceed 16MB. The resulting document's structure depends on the command, but most results will have the ok field to indicate success or failure and results containing an array of each of the resulting documents.

Примеры

Пример #1 MongoDB::command() "distinct" example

Finding all of the distinct values for a key.


<?php

$people = $db->people;

$people->insert(array("name" => "Joe", "age" => 4));
$people->insert(array("name" => "Sally", "age" => 22));
$people->insert(array("name" => "Dave", "age" => 22));
$people->insert(array("name" => "Molly", "age" => 87));

$ages = $db->command(array("distinct" => "people", "key" => "age"));

foreach ($ages['values'] as $age) {
    echo "$age\n";
}

?>

Результатом выполнения данного примера будет что-то подобное:

4
22
87

Пример #2 MongoDB::command() "distinct" example

Finding all of the distinct values for a key, where the value is larger than or equal to 18.


<?php

$people = $db->people;

$people->insert(array("name" => "Joe", "age" => 4));
$people->insert(array("name" => "Sally", "age" => 22));
$people->insert(array("name" => "Dave", "age" => 22));
$people->insert(array("name" => "Molly", "age" => 87));

$ages = $db->command(
    array(
        "distinct" => "people",
        "key" => "age", 
        "query" => array("age" => array('$gte' => 18))
    )
);  

foreach ($ages['values'] as $age) {
    echo "$age\n";
}

?>

Результатом выполнения данного примера будет что-то подобное:

22
87

Пример #3 MongoDB::command() MapReduce example

Get all users with at least on "sale" event, and how many times each of these users has had a sale.


<?php

// sample event document
$events->insert(array("user_id" => $id, 
    "type" => $type, 
    "time" => new MongoDate(), 
    "desc" => $description));

// construct map and reduce functions
$map = new MongoCode("function() { emit(this.user_id,1); }");
$reduce = new MongoCode("function(k, vals) { ".
    "var sum = 0;".
    "for (var i in vals) {".
        "sum += vals[i];". 
    "}".
    "return sum; }");

$sales = $db->command(array(
    "mapreduce" => "events", 
    "map" => $map,
    "reduce" => $reduce,
    "query" => array("type" => "sale"),
    "out" => array("merge" => "eventCounts")));

$users = $db->selectCollection($sales['result'])->find();

foreach ($users as $user) {
    echo "{$user['_id']} had {$user['value']} sale(s).\n";
}

?>

Результатом выполнения данного примера будет что-то подобное:

User 47cc67093475061e3d9536d2 had 3 sale(s).
User 49902cde5162504500b45c2c had 14 sale(s).
User 4af467e4fd543cce7b0ea8e2 had 1 sale(s).

Замечание: Using MongoCode

This example uses MongoCode, which can also take a scope argument. However, at the moment, MongoDB does not support using scopes in MapReduce. If you would like to use client-side variables in the MapReduce functions, you can add them to the global scope by using the optional scope field with the database command. See the » MapReduce documentation for more information.

Замечание: The out argument

Before 1.8.0, the out argument was optional. If you did not use it, MapReduce results would be written to a temporary collection, which would be deleted when your connection was closed. In 1.8.0+, the out argument is required. See the » MapReduce documentation for more information.

If you are going to be using MapReduce, Prajwal Tuladhar created an API for Mongo PHP users which provides a nicer interface than the bare command. You can download it from » Github and there is a » blog post on how to use it.

Пример #4 MongoDB::command() "textSearch" example

Do a fulltext search lookup with MongoDB's 2.4 and higher "text search" functionality.


<?php
$m = new MongoClient();
$d = $m->demo;
$c = $d->planets;

$c->insert(array("name" => "Mercury", "desc" => "Mercury is the smallest and closest to the Sun"));
$c->insert(array("name" => "Venus", "desc" => "Venus is the second planet from the Sun, orbiting it every 224.7 Earth days."));
$c->insert(array("name" => "Earth", "desc" => "Earth is the the densest of the eight planets in the Solar System."));
$c->insert(array("name" => "Mars", "desc" => "Mars is named after the Roman god of war."));

$c->ensureIndex(array('desc' => 'text'));

$r = $d->command(array("text" => "planets", 'search' => "sun" ));
print_r($r);
?>

Результатом выполнения данного примера будет что-то подобное:

Array
(
[queryDebugString] => sun||||||
[language] => english
[results] => Array
(
[0] => Array
(
[score] => 0.625
[obj] => Array
(
[_id] => MongoId Object
(
[$id] => 517549d944670a4a5cb3059a
)

[name] => Mercury
[desc] => Mercury is the smallest and closest to the Sun
)

)

[1] => Array
(
[score] => 0.55
[obj] => Array
(
[_id] => MongoId Object
(
[$id] => 517549d944670a4a5cb3059b
)

[name] => Venus
[desc] => Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.
)

)

)

[stats] => Array
(
[nscanned] => 2
[nscannedObjects] => 0
[n] => 2
[nfound] => 2
[timeMicros] => 95
)

[ok] => 1
)

Пример #5 MongoDB::command() "geoNear" example

This example shows how to use the geoNear command.


<?php
$m = new MongoClient();
$d = $m->demo;
$c = $d->poiConcat;

$r = $d->command(array(
    'geoNear' => "poiConcat",      // Search in the poiConcat collection
    'near' => array(-0.08, 51.48), // Search near 51.48°N, 0.08°E
    'spherical' => true,           // Enable spherical search
    'num' => 5,                    // Maximum 5 returned documents
));
print_r($r);
?>

Смотрите также

MongoCollection::aggregate() - Perform an aggregation using the aggregation framework
MongoCollection::findAndModify() - Update a document and return it
MongoCollection::group() - Performs an operation similar to SQL's GROUP BY command

MongoDB core docs on » database commands and on individual commands: » findAndModify, » getLastError, and » repair (dozens more exist, there are merely a few examples).

MongoDB::__construct

MongoDB::authenticate

[edit] Last updated: Fri, 07 Jun 2013

add a note User Contributed Notes MongoDB::command - [4 notes]

down

mcuadros at gmail dot com ¶

2 months ago


Command of Mongo 2.4 Text Search feature.



<?php

$result = $db->command(

    array(

        'text' => 'bar', //this is the name of the collection where we are searching

        'search' => 'hotel', //the string to search

        'limit' => 5, //the number of results, by default is 1000

        'project' => Array( //the fields to retrieve from db

            'title' => 1

        )

    )

);

down

Min He ¶

2 years ago


rename a collection: 





<?php


$m = new Mongo();


$adminDB = $m->admin; //require admin priviledge





//rename collection 'colA' in db 'yourdbA' to collection 'colB' in another db 'yourdbB'





$res = $adminDB->command(array(


    "renameCollection" => "yourdbA.colA",


    "to" => "yourdbB.colB"


));





var_dump($res);


?>

down

Anonymous ¶

2 years ago


> Need to know the database version? There's a command for that.



We didn't find it - ended up using either;



<?php

$m = new Mongo();



$adminDB = $m->admin; //require admin priviledge



$mongodb_info = $adminDB->command(array('buildinfo'=>true));

$mongodb_version = $mongodb_info['version'];



print_r($mongodb_info);

?>



or



<?php

$v = `mongo --version`;

print_r($v);

?>

down

roman dot drapeko at gmail dot com ¶

2 years ago


I tried to write MapReduce. Unfortunately, out => array('replace' => 'collName') did not work for me. Instead, the below code works





<?php


$mongo->command(array(


     'mapreduce' => 'events',


     'map' => $map,


     'reduce' => $reduce,


     'out' => 'mapReduceEventStats'


));


?>

add a note