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public mapReduce ( MongoDB\BSON\Javascript | string $map, MongoDB\BSON\Javascript | string $reduce, string | array $out, array $condition = [], array $options = [] ) : string | array |
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$map |
MongoDB\BSON\Javascript | string |
function, which emits map data from collection.
Argument will be automatically cast to [[\MongoDB\BSON\Javascript]]. |
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$reduce |
MongoDB\BSON\Javascript | string |
function that takes two arguments (the map key
and the map values) and does the aggregation.
Argument will be automatically cast to [[\MongoDB\BSON\Javascript]]. |
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$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. |
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$condition |
array |
criteria for including a document in the aggregation. |
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$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: int, 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: bool, specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions.
- verbose: bool, specifies whether to include the timing information in the result information. |
| return |
string | array |
the map reduce output collection name or output results. |