mongodb\Command mapReduce()

mapReduce() public method

Performs MongoDB "map-reduce" command.

public string|array mapReduce ( $collectionName, $map, $reduce, $out, $condition = [], $options = [] )
$collectionName string

Collection name.

$map \MongoDB\BSON\Javascript|string

Function, which emits map data from collection. Argument will be automatically cast to \MongoDB\BSON\Javascript.

$reduce \MongoDB\BSON\Javascript|string

Function that takes two arguments (the map key and the map values) and does the aggregation. Argument will be automatically cast to \MongoDB\BSON\Javascript.

$out string|array

Output collection name. It could be a string for simple output ('outputCollection'), or an array for parametrized output (['merge' => 'outputCollection']). You can pass ['inline' => true] to fetch the result at once without temporary collection usage.

$condition array

Filter condition for including a document in the aggregation.

$options array

Additional optional parameters to the mapReduce command. Valid options include:

  • sort: array, key to sort the input documents. The sort key must be in an existing index for this collection.
  • limit: integer, the maximum number of documents to return in the collection.
  • finalize: \MongoDB\BSON\Javascript|string, function, which follows the reduce method and modifies the output.
  • scope: array, specifies global variables that are accessible in the map, reduce and finalize functions.
  • jsMode: boolean, specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions.
  • verbose: boolean, specifies whether to include the timing information in the result information.
return string|array

The map reduce output collection name or output results.

doc_Yii
2016-10-30 17:07:51
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