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MongoDB::command

(PECL mongo >=0.9.2)

MongoDB::commandExecute a database command

Description

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);
}

?>

Parameters

command

The query to send.

options

An array of options for the index creation. Currently available options include:

  • "socketTimeoutMS"

    This option specifies the time limit, in milliseconds, for socket communication. If the server does not respond within the timeout period, a MongoCursorTimeoutException will be thrown and there will be no way to determine if the server actually handled the write or not. A value of -1 may be specified to block indefinitely. The default value for MongoClient is 30000 (30 seconds).

The following options are deprecated and should no longer be used:

  • "timeout"

    Deprecated alias for "socketTimeoutMS".

Changelog

Version Description
1.5.0

Renamed the "timeout" option to "socketTimeoutMS". Emits E_DEPRECATED when "timeout" is used.

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

Return Values

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.

Examples

Example #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";
}

?>

The above example will output something similar to:


4
22
87

Example #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";
}

?>

The above example will output something similar to:


22
87

Example #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";
}

?>

The above example will output something similar to:


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

Note: 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.

Note: 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.

Example #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 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);
?>

The above example will output something similar to:


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
)

Example #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(-0.0851.48), // Search near 51.48°N, 0.08°E
    
'spherical' => true,           // Enable spherical search
    
'num' => 5,                    // Maximum 5 returned documents
));
print_r($r);
?>

See Also

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

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User Contributed Notes 5 notes

up
3
Min He
4 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);
?>
up
1
roman dot drapeko at gmail dot com
3 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'
));
?>
up
0
mcuadros at gmail dot com
1 year 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
       
)
    )
);
up
0
Anonymous
3 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);
?>
up
-1
nanhe dot kumar at gmail dot com
1 year ago
$db=new new Mongo();

Copy old_db to new_db

$responseCopy = $db->admin->command(array(
    'copydb' => 1,
    'fromhost' => 'localhost',
    'fromdb' => 'old_db',
    'todb' =>'new_db'
    ));

Now drop old_db

if($responseCopy['ok']==1){
$responseDrop=$db->old_db->command(array('dropDatabase' => 1));
//OR
$responseDrop =$db->old_db->drop();
}

Show Output

print_r($responseCopy);
print_r($responseDrop);

Output will be something like this

Array ( [ok] => 1 )
Array ( [dropped] => old_db [ok] => 1 )
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