No cache version.
Caching disabled. Default setting for this page:enabled (code LNG204)If the display is too slow, you can disable the user mode to view the cached version.
The MongoCommandCursor class
(PECL mongo >=1.5.0)
Introduction
A command cursor is similar to a MongoCursor except that you use it for iterating through the results of a database command instead of a normal query. Command cursors are useful for iterating over large result sets that might exceed the document size limit (currently 16MB) of a single MongoDB::command() response.
While you can create command cursors using MongoCommandCursor::__construct() or the MongoCommandCursor::createFromDocument() factory method, you will generally want to use command-specific helpers such as MongoCollection::aggregateCursor().
Note that the cursor does not "contain" the database command's results; it just manages iteration through them. Thus, if you print a cursor (f.e. with var_dump() or print_r()), you will see the cursor object but not the result documents.
Cursor Stages
A MongoCommandCursor has two "life stages": pre- and post- command. When a cursor is created, it has not yet contacted the database, so it is in its pre-command state. When the client first attempts to get a result (by calling MongoCommandCursor::rewind(), directly or indirectly), the cursor moves into the post-command state.
The command cursor's batch size and socket timeout may be configured in both the pre- and post- command states.
Example #1 Adding options to MongoCommandCursor
<?php
$cursor = new MongoCommandCursor(...);
$cursor = $cursor->batchSize( 4 );
foreach ($cursor as $result) {
var_dump($result);
}
?>
Class synopsis
$connection
, string $hash
, array $document
) : MongoCommandCursorTable of Contents
- MongoCommandCursor::batchSize — Limits the number of elements returned in one batch
- MongoCommandCursor::__construct — Create a new command cursor
- MongoCommandCursor::createFromDocument — Create a new command cursor from an existing command response document
- MongoCommandCursor::current — Returns the current element
- MongoCommandCursor::dead — Checks if there are results that have not yet been sent from the database
- MongoCommandCursor::getReadPreference — Get the read preference for this command
- MongoCommandCursor::info — Gets information about the cursor's creation and iteration
- MongoCommandCursor::key — Returns the current result's index within the result set
- MongoCommandCursor::next — Advances the cursor to the next result
- MongoCommandCursor::rewind — Executes the command and resets the cursor to the start of the result set
- MongoCommandCursor::setReadPreference — Set the read preference for this command
- MongoCommandCursor::timeout — Sets a client-side timeout for this command
- MongoCommandCursor::valid — Checks if the cursor is reading a valid result
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-class.mongocommandcursor.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.
