The MongoDB class

(PECL mongo >=0.9.0)

Introduction

Instances of this class are used to interact with a database. To get a database:

Example #1 Selecting a database

<?php

$m 
= new MongoClient(); // connect
$db $m->selectDB("example");

?>
Database names can use almost any character in the ASCII range. However, they cannot contain " ", "." or be the empty string. The name "system" is also reserved.

A few unusual, but valid, database names: "null", "[x,y]", "3", "\"", "/".

Unlike collection names, database names may contain "$".

Class synopsis

MongoDB {
/* Constants */
const int PROFILING_OFF = 0 ;
const int PROFILING_SLOW = 1 ;
const int PROFILING_ON = 2 ;
/* Fields */
public integer $w = 1 ;
public integer $wtimeout = 10000 ;
/* Methods */
public authenticate ( string $username , string $password ) : array
public command ( array $command [, array $options = array() [, string &$hash ]] ) : array
public __construct ( MongoClient $conn , string $name )
public createCollection ( string $name [, array $options ] ) : MongoCollection
public createDBRef ( string $collection , mixed $document_or_id ) : array
public drop ( void ) : array
public dropCollection ( mixed $coll ) : array
public execute ( mixed $code [, array $args = array() ] ) : array
public forceError ( void ) : bool
public __get ( string $name ) : MongoCollection
public getCollectionInfo ([ array $options = array() ] ) : array
public getCollectionNames ([ array $options = array() ] ) : array
public getDBRef ( array $ref ) : array
public getGridFS ([ string $prefix = "fs" ] ) : MongoGridFS
public getProfilingLevel ( void ) : int
public getReadPreference ( void ) : array
public getSlaveOkay ( void ) : bool
public getWriteConcern ( void ) : array
public lastError ( void ) : array
public listCollections ([ array $options = array() ] ) : array
public prevError ( void ) : array
public repair ([ bool $preserve_cloned_files = FALSE [, bool $backup_original_files = FALSE ]] ) : array
public resetError ( void ) : array
public selectCollection ( string $name ) : MongoCollection
public setProfilingLevel ( int $level ) : int
public setReadPreference ( string $read_preference [, array $tags ] ) : bool
public setSlaveOkay ([ bool $ok = TRUE ] ) : bool
public setWriteConcern ( mixed $w [, int $wtimeout ] ) : bool
public __toString ( void ) : string
}

Predefined Constants

MongoDB Log Levels

MongoDB::PROFILING_OFF
Profiling is off.
MongoDB::PROFILING_SLOW
Profiling is on for slow operations (>100 ms).
MongoDB::PROFILING_ON
Profiling is on for all operations.

Fields

w
1

The number of servers to replicate a change to before returning success. Inherited by instances of MongoCollection derived from this. w functionality is only available in version 1.5.1+ of the MongoDB server and 1.0.8+ of the driver.

w is used whenever you need to adjust the acknowledgement level (MongoCollection::insert(), MongoCollection::update(), MongoCollection::remove(), MongoCollection::save(), and MongoCollection::ensureIndex() all support this option). With the default value (1), an acknowledged operation will return once the database server has the operation. If the server goes down before the operation has been replicated to a secondary, it is possible to lose the operation forever. Thus, you can specify w to be higher than one and guarantee that at least one secondary has the operation before it is considered successful.

For example, if w is 2, the primary and one secondary must have a record of the operation or the driver will throw a MongoCursorException. It is tempting to set w to the total number of secondaries + primary, but then if one secondary is down the operation will fail and an exception will be thrown, so usually w=2 is safest (primary and one secondary).

wtimeout
10000

The number of milliseconds to wait for MongoDB::$w replications to take place. Inherited by instances of MongoCollection derived from this. w functionality is only available in version 1.5.1+ of the MongoDB server and 1.0.8+ of the driver.

Unless wtimeout is set, the server waits forever for replicating to w servers to finish. The driver defaults to waiting for 10 seconds, you can change this value to alter its behavior.

See Also

MongoDB core docs on » databases.

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