Class yii\mongodb\BatchQueryResult

All Classes | Properties | Methods

Inheritance	yii\mongodb\BatchQueryResult » yii\base\BaseObject
Implements	Iterator
Available since extension's version	2.1
Source Code	https://github.com/yiisoft/yii2-mongodb/blob/master/src/BatchQueryResult.php

BatchQueryResult represents a batch query from which you can retrieve data in batches.

You usually do not instantiate BatchQueryResult directly. Instead, you obtain it by calling yii\mongodb\Query::batch() or yii\mongodb\Query::each(). Because BatchQueryResult implements the Iterator interface, you can iterate it to obtain a batch of data in each iteration. For example,

$query = (new Query())->from('user');
foreach ($query->batch() as $i => $users) {
    // $users represents the rows in the $i-th batch
}
foreach ($query->each() as $user) {
}

Public Properties

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Property	Type	Description	Defined By
$batchSize	integer	The number of rows to be returned in each batch.	yii\mongodb\BatchQueryResult
$db	yii\mongodb\Connection	The MongoDB connection to be used when performing batch query.	yii\mongodb\BatchQueryResult
$each	boolean	Whether to return a single row during each iteration.	yii\mongodb\BatchQueryResult
$query	yii\mongodb\Query	The query object associated with this batch query.	yii\mongodb\BatchQueryResult

Public Methods

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Method	Description	Defined By
current()	Returns the current dataset.	yii\mongodb\BatchQueryResult
key()	Returns the index of the current dataset.	yii\mongodb\BatchQueryResult
next()	Moves the internal pointer to the next dataset.	yii\mongodb\BatchQueryResult
reset()	Resets the batch query.	yii\mongodb\BatchQueryResult
rewind()	Resets the iterator to the initial state.	yii\mongodb\BatchQueryResult
valid()	Returns whether there is a valid dataset at the current position.	yii\mongodb\BatchQueryResult

Protected Methods

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Method	Description	Defined By
fetchData()	Fetches the next batch of data.	yii\mongodb\BatchQueryResult

Property Details

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$batchSize public property

The number of rows to be returned in each batch.

public integer $batchSize = 100

$db public property

The MongoDB connection to be used when performing batch query. If null, the "mongodb" application component will be used.

public yii\mongodb\Connection $db = null

$each public property

Whether to return a single row during each iteration. If false, a whole batch of rows will be returned in each iteration.

public boolean $each = false

$query public property

The query object associated with this batch query. Do not modify this property directly unless after reset() is called explicitly.

public yii\mongodb\Query $query = null

Method Details

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current() public method

Returns the current dataset.

This method is required by the interface Iterator.

public mixed current ( )
return	mixed	The current dataset.

Source code

                #[\ReturnTypeWillChange]
public function current()
{
    return $this->_value;
}

fetchData() protected method

Fetches the next batch of data.

protected array fetchData ( )
return	array	The data fetched

Source code

                protected function fetchData()
{
    if ($this->_iterator === null) {
        $this->query->addOptions(['batchSize' => $this->batchSize]);
        $cursor = $this->query->buildCursor($this->db);
        $token = 'fetch cursor id = ' . $cursor->getId();
        Yii::info($token, __METHOD__);
        if ($cursor instanceof \Iterator) {
            $this->_iterator = $cursor;
        } else {
            $this->_iterator = new \IteratorIterator($cursor);
        }
        $this->_iterator->rewind();
    }
    $rows = [];
    $count = 0;
    while ($count++ < $this->batchSize) {
        if (!$this->_iterator->valid()) {
            break;
        }
        $rows[] = $this->_iterator->current();
        $this->_iterator->next();
    }
    return $this->query->populate($rows);
}

key() public method

Returns the index of the current dataset.

This method is required by the interface Iterator.

public integer key ( )
return	integer	The index of the current row.

Source code

                #[\ReturnTypeWillChange]
public function key()
{
    return $this->_key;
}

next() public method

Moves the internal pointer to the next dataset.

This method is required by the interface Iterator.

public void next ( )

Source code

                #[\ReturnTypeWillChange]
public function next()
{
    if ($this->_batch === null || !$this->each || $this->each && next($this->_batch) === false) {
        $this->_batch = $this->fetchData();
        reset($this->_batch);
    }
    if ($this->each) {
        $this->_value = current($this->_batch);
        if ($this->query->indexBy !== null) {
            $this->_key = key($this->_batch);
        } elseif (key($this->_batch) !== null) {
            $this->_key = $this->_key === null ? 0 : $this->_key + 1;
        } else {
            $this->_key = null;
        }
    } else {
        $this->_value = $this->_batch;
        $this->_key = $this->_key === null ? 0 : $this->_key + 1;
    }
}

reset() public method

Resets the batch query.

This method will clean up the existing batch query so that a new batch query can be performed.

public void reset ( )

Source code

                #[\ReturnTypeWillChange]
public function reset()
{
    $this->_iterator = null;
    $this->_batch = null;
    $this->_value = null;
    $this->_key = null;
}

rewind() public method

Resets the iterator to the initial state.

This method is required by the interface Iterator.

public void rewind ( )

Source code

                #[\ReturnTypeWillChange]
public function rewind()
{
    $this->reset();
    $this->next();
}

valid() public method

Returns whether there is a valid dataset at the current position.

This method is required by the interface Iterator.

public boolean valid ( )
return	boolean	Whether there is a valid dataset at the current position.

Source code

                public function valid(): bool
{
    return !empty($this->_batch);
}