Aggregation Reference¶

Aggregation Operator Quick Reference: Quick reference card for aggregation pipeline.
Aggregation Framework Operators: Aggregation pipeline operations have a collection of operators available to define and manipulate documents in pipeline stages.
Aggregation Commands Comparison: A comparison of group, mapReduce and aggregate that explores the strengths and limitations of each aggregation modality.
SQL to Aggregation Mapping Chart: An overview common aggregation operations in SQL and MongoDB using the aggregation pipeline and operators in MongoDB and common SQL statements.
Aggregation Interfaces: The data aggregation interfaces document the invocation format and output for MongoDB’s aggregation commands and methods.
Variables in Aggregation: Use of variables in aggregation pipeline expressions.