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    MongoCollection::aggregateCursor

    (PECL mongo >=1.5.0)

    MongoCollection::aggregateCursor — Execute an aggregation pipeline command and retrieve results through a cursor

    Descrierea

    public MongoCollection::aggregateCursor ( array $command , array $options = ? ) : MongoCommandCursor

    With this method you can execute Aggregation Framework pipelines and retrieve the results through a cursor, instead of getting just one document back as you would with MongoCollection::aggregate(). This method returns a MongoCommandCursor object. This cursor object implements the Iterator interface just like the MongoCursor objects that are returned by the MongoCollection::find() method.

    Notă: The resulting MongoCommandCursor will inherit this collection's read preference. MongoCommandCursor::setReadPreference() may be used to change the read preference before iterating on the cursor.

    Parametri

    pipeline

    The Aggregation Framework pipeline to execute.

    options

    Options for the aggregation command. Valid options include:

    • "allowDiskUse"

      Allow aggregation stages to write to temporary files

    • "cursor"

      It is possible to configure how many initial documents the server should return with the first result set. The default initial batch size is 101. You can change it by adding the batchSize option:

      <?php
      $collection      ->aggregateCursor( 
                $pipeline,
          [       "cursor" => [ "batchSize" => 4 ] ]
      );

      This option only configures the size of the first batch. To configure the size of future batches, please use the MongoCommandCursor::batchSize() method on the returned MongoCommandCursor object.

    • "explain"

      Return information on the processing of the pipeline. This option may cause the command to return a result document that is unsuitable for constructing a MongoCommandCursor. If you need to use this option, you should consider using MongoCollection::aggregate().

    • "maxTimeMS"

      Specifică o limită de timp cumulativă în milisecunde pentru procesarea operațiunii pe server (nu include timpul de așteptare). Dacă operațiunea nu este terminată pe server în timpul rezervat, va fi emisă o MongoExecutionTimeoutException.

    Valorile întoarse

    Returns a MongoCommandCursor object. Because this implements the Iterator interface you can iterate over each of the results as returned by the command query. The MongoCommandCursor also implements the MongoCursorInterface interface which adds the MongoCommandCursor::batchSize(), MongoCommandCursor::dead(), MongoCommandCursor::info() methods.

    Exemple

    Example #1 MongoCollection::aggregateCursor() example

    Finding all of the distinct values for a key.

    <?php
    $m     = new MongoClient;
    $db = $m->test;
    $people = $db->people;
    $people->drop();

    $people->insert(array("name" => "Joe", "points" => 4));
    $people->insert(array("name" => "Molly", "points" => 43));
    $people->insert(array("name" => "Sally", "points" => 22));
    $people->insert(array("name" => "Joe", "points" => 22));
    $people->insert(array("name" => "Molly", "points" => 87));

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

    foreach (    $ages as $person) {
        echo     "{$person['_id']}: {$person['points']}\n";
    }

    ?>

    Exemplul de mai sus va afișa ceva similar cu:


    Molly: 130
    Joe: 26
    Sally: 22

    Example #2 MongoCollection::aggregateCursor() example with different initial batch size

    Finding all of the distinct values for a key.

    <?php
    $m     = new MongoClient;
    $db = $m->test;
    $people = $db->people;
    $people->drop();

    /* Insert some sample data */
    $people->insert(array("name" => "Joe", "points" => 4));
    $people->insert(array("name" => "Molly", "points" => 43));
    $people->insert(array("name" => "Sally", "points" => 22));
    $people->insert(array("name" => "Joe", "points" => 22));
    $people->insert(array("name" => "Molly", "points" => 87));

    /* Run the command cursor */
    $ages = $people->aggregateCursor(
        [
            [     '$group' => [ '_id' => '$name', 'points' => [ '$sum' => '$points' ] ] ],
            [     '$sort' => [ 'points' => -1 ] ],
        ],
        [     "cursor" => [ "batchSize" => 4 ] ]
    );

    foreach (    $ages as $person) {
        echo     "{$person['_id']}: {$person['points']}\n";
    }

    ?>

    Exemplul de mai sus va afișa ceva similar cu:


    Molly: 130
    Joe: 26
    Sally: 22

    A se vedea și

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    User Contributed Notes 2 notes

    up
    1
    Dmitriy
    6 years ago
    aggregateCursor with mongoDB 3.6 can cause error:
    "the command cursor did not return a correctly structured response"

    to fix it on 64 bit systems, temporarily turn on:
    ini_set('mongo.long_as_object', true);
    up
    1
    lukasz at endai dot com
    9 years ago
    It looks like maxTimeMS option in the latest release (1.5.8) is not valid anymore. Set \MongoCursor::$timeout before you call aggregateCursor()
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