[edit] Last updated: Fri, 18 Sep 2009

The MongoCursor class

Увод

Result object for database query.

The database is not actually queried until next() or hasNext() is called. Before the database is queried, commands can be strung together, as in:

<?php
$cursor = $collection->find()->limit(10);

// database has not yet been queried, so more search options can be added
$cursor = $cursor->sort(array("a" => 1));

var_dump($cursor->getNext());
// now database has been queried and more options cannot be added

// so this will throw an exception:
$cursor->skip(4);
?>

Синтаксис за класове

MongoCursor

implements Iterator {

/* Static Fields */

static boolean $slaveOkay = FALSE ;

/* Methods */

__construct ( resource $connection , string $ns [, array $query = array() [, array $fields = array() ]] )

public int count ( void )

public array current ( void )

protected void doQuery ( void )

public array explain ( void )

public array getNext ( void )

public boolean hasNext ( void )

public MongoCursor hint ( array $key_pattern )

public string key ( void )

public MongoCursor limit ( int $num )

public void next ( void )

public void reset ( void )

public void rewind ( void )

public MongoCursor skip ( int $num )

public MongoCursor slaveOkay ([ boolean $okay = true ] )

public MongoCursor sort ( array $fields )

public MongoCursor tailable ([ boolean $tail = true ] )

public boolean valid ( void )

}

Съдържание

MongoCursor::__construct — Create a new cursor
MongoCursor::count — Counts the number of results for this query
MongoCursor::current — Returns the current result
MongoCursor::doQuery — Execute the query.
MongoCursor::explain — Return an explanation of the query, often useful for optimization and debugging
MongoCursor::getNext — Return the next object to which this cursor points, and advance the cursor
MongoCursor::hasNext — Checks if there are any more elements in this cursor
MongoCursor::hint — Gives the database a hint about the query
MongoCursor::key — Returns the current result's _id
MongoCursor::limit — Limits the number of results returned
MongoCursor::next — Advances the cursor to the next result
MongoCursor::reset — Clears the cursor
MongoCursor::rewind — Returns the cursor to the beginning of the result set
MongoCursor::skip — Skips a number of results
MongoCursor::slaveOkay — Sets whether this query can be done on a slave
MongoCursor::sort — Sorts the results by given fields
MongoCursor::tailable — Sets whether this cursor will be left open after fetching the last results
MongoCursor::valid — Checks if the cursor is reading a valid result.

add a note User Contributed Notes MongoCursor

adrian dot zurek at netmedia dot com dot pl 24-Oct-2011 04:08


One *VERY* important note, if You do:

$cursor = $collection->find(array(), array('_id' => 0)); // ommit '_id' field in result 



then:

var_dump(iterator_to_array($cursor));



will return only *ONE* document, not all!

Adil Baig @ AiDezigns 07-Sep-2011 07:28


If you want to know whether a cursor returned any results it is faster to use 'hasNext()' than 'count'

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