(PECL mongo >=0.9.2)
MongoDB::command — Execute a database command
$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);
}
?>
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".
| Versione | Descrizione |
|---|---|
| 1.5.0 |
Renamed the "timeout" option to
"socketTimeoutMS". Emits
|
| 1.2.0 | Added options parameter with a single option: "timeout". |
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.
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";
}
?>
Il precedente esempio visualizzerà qualcosa simile a:
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";
}
?>
Il precedente esempio visualizzerà qualcosa simile a:
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";
}
?>
Il precedente esempio visualizzerà qualcosa simile a:
Nota: 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.
Nota: 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);
?>
Il precedente esempio visualizzerà qualcosa simile a:
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 = $d->command(array(
'geoNear' => "poiConcat", // Search in the poiConcat collection
'near' => array(-0.08, 51.48), // Search near 51.48°N, 0.08°E
'spherical' => true, // Enable spherical search
'num' => 5, // Maximum 5 returned documents
));
print_r($r);
?>
MongoDB core docs on » database commands and on individual commands: » findAndModify, » getLastError, and » repairDatabase (dozens more exist, there are merely a few examples).