How to Use Aggregate Queries in MongoDB Version 2.0.6

  mongodb, question

The MongoDB 2.4 version began to have Aggregat () and Pineline () pipeline queries, but how to use this function in the 2.0.6 version, because the 2.0.6 method does not have aggregate. So how to realize aggregate grouping query? Group () method is required.

Aggregation is a new function added in 2.2. map/reduce was considered in earlier versions.