# 聚合参考

* [聚合管道快速参考](/aggregation/aggregation-reference/aggregation-pipeline-quick-reference.md)

  聚合管道的快速参考卡。
* [聚合命令](/aggregation/aggregation-reference/aggregation-commands.md)

  数据聚合命令的引用，该命令为MongoDB的聚合功能提供接口。
* [聚合命令比较](/aggregation/aggregation-reference/aggregation-commands-commparison.md)

  [MapReduce](/aggregation/aggregation-reference.md)和[Aggregate](/aggregation/aggregation-reference.md)命令的比较。
* [聚合管道操作符](/can-kao/yun-suan-fu/aggregation-pipeline-operators.md)

  聚合管道操作有一个操作符集合，可用于在管道阶段中定义和操作文档。
* [聚合表达式中的变量](/aggregation/aggregation-reference/variables-in-aggregation-expressions.md)

  在聚合管道表达式中使用变量。
* [SQL 到聚合映射图表](/aggregation/aggregation-reference/sql-to-aggregation-mapping-chart.md)

  使用MongoDB和常见SQL语句中的聚合管道和操作符概述SQL和MongoDB中的常见聚合操作。

译者：李冠飞

校对：李冠飞


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