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= aggregate() =
----
[[MongoDB Driver Function Reference]]


Runs an aggregation on a collection and retrieves the results.
More information can be found in the corresponding entry of the [[https://docs.mongodb.com/manual/reference/method/db.collection.aggregate/index.html|MongoDB Manual]].


[[[@cG

<collection>.aggregate([<pipeline>[, <options>]])

]]]


**Arguments**

[[[@w

|@t0@r0@c0 <collection> | | The target collection. |
| <pipeline> | | An array of BSON documents specifying the [[https://docs.mongodb.com/manual/core/aggregation-pipeline/#id1|aggregation pipline]]. |
| <options> | | A BOSN document specifying options. |

]]]


**Options**

[[[@cw

{ allowDiskUse: <boolean>, batchSize: <int>, comment: <string>, maxAwaitTime: <long>,
collation: <document>, hint: <document>, bypass }
<<@f:text>>
|@t0@r0@c0 allowDiskUse | | Allows to write to disk while executing. |
| batchSize | | Sets the batch size. |
| bypassDocumentValidation | | Document validation will be bypassed (default; false), |
| comment | | Sets the comment. |
| maxAwaitTime | | Sets the maximum await time (in milliseconds). |
| collation | | A document specifying the [[https://docs.mongodb.com/manual/reference/bson-type-comparison-order/#collation|collation]]. |
| hint | | A document specifying a [[https://docs.mongodb.com/manual/reference/method/db.collection.deleteMany/#ex-deletemany-hint|hint]]. |
<<@/f>>
]]]


**Return Value**

[[[@w

Returns a result set (cursor).

]]]


**Example**

[[[@cw

db.employees.aggregate([{ $match: {salary: { $gt: 1000000 }}}]);

]]]

Returns the aggregated documents.



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