Aggregation

In version 2.2, MongoDB introduced the aggregation framework that provides a powerful and flexible set of tools to use for many data aggregation tasks. If you’re familiar with data aggregation in SQL, consider the SQL to Aggregation Framework Mapping Chart document as an introduction to some of the basic concepts in the aggregation framework. Consider the full documentation of the aggregation framework and other data aggregation tools for MongoDB here:

• 聚合应用框架
• 聚合应用框架示例
• 聚合应用框架参考
• SQL to Aggregation Framework Mapping Chart
• Map-Reduce
  • Map-Reduce Examples
  • Perform Incremental Map-Reduce
  • Troubleshoot the Map Function
  • Troubleshoot the Reduce Function
• Simple Aggregation Methods and Commands

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• Aggregation Framework  >