mongodb\Command mapReduce()

Collection name.

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

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.

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.

Filter condition for including a document in the aggregation.

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.

The map reduce output collection name or output results.