> 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);
?>
MongoDB::command
(PECL mongo >=0.9.2)
MongoDB::command — Execute a database command
Description
public MongoDB::command
( array
$command
[, array $options = array()
[, string &$hash
]] ) : arrayAlmost 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
-1may be specified to block indefinitely. The default value for MongoClient is30000(30 seconds).
The following options are deprecated and should no longer be used:
"timeout"Deprecated alias for
"socketTimeoutMS".
-
hash -
Set to the connection hash of the server that executed the command. When the command result is suitable for creating a MongoCommandCursor, the hash is intended to be passed to MongoCommandCursor::createFromDocument().
The hash will also correspond to a connection returned from MongoClient::getConnections().
Changelog
| Version | Description |
|---|---|
| 1.5.0 |
Renamed the
Added |
| 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
outargument
Before 1.8.0, the
outargument 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+, theoutargument is required. See the » MapReduce documentation for more information.
Example #4 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);
?>
See Also
- 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.
add a note
User Contributed Notes 5 notes
Anonymous ¶
13 years ago
Min He ¶
14 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);
?>
mcuadros at gmail dot com ¶
11 years 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
)
)
);
roman dot drapeko at gmail dot com ¶
13 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'
));
?>
nanhe dot kumar at gmail dot com ¶
11 years 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 )
