MongoCommandCursor::getReadPreference

(PECL mongo >=1.6.0)

MongoCommandCursor::getReadPreference — Get the read preference for this command

Beschreibung

public MongoCommandCursor::getReadPreference ( void ) : array

Parameter-Liste

Diese Funktion besitzt keine Parameter.

Rückgabewerte

This function returns an array describing the read preference. The array contains the values type for the string read preference mode (corresponding to the MongoClient constants), and tagsets containing a list of all tag set criteria. If no tag sets were specified, tagsets will not be present in the array.

Beispiele

Beispiel #1 MongoCommandCursor::getReadPreference() return value example

<?php

$m = new MongoClient('mongodb://rs1.example.com:27017', array('replicaSet' => 'myReplSetName'));
$collection = $m->selectCollection('test', 'people');

// If a MongoCommandCursor is constructed directly, it will inherit the read
// preference of the MongoClient instance passed to its constructor; however,
// MongoCollection::aggregateCursor() will have the MongoCommandCursor inherit
// the collection's read preference.
$collection->setReadPreference(MongoClient::RP_SECONDARY);

$cursor = $collection->aggregateCursor( [
    [ '$group' => [ '_id' => '$name', 'points' => [ '$sum' => '$points' ] ] ],
    [ '$sort' => [ 'points' => -1 ] ],
] );

var_dump($cursor->getReadPreference());

?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

array(1) {
  ["type"]=>
  string(9) "secondary"
}

Siehe auch