aggregation pipeline - mmedrano9438/peripheral-brain GitHub Wiki

An aggregation pipeline consists of one or more stages that process documents:

Each stage performs an operation on the input documents. For example, a stage can filter documents, group documents, and calculate values.

The documents that are output from a stage are passed to the next stage.

An aggregation pipeline can return results for groups of documents. For example, return the total, average, maximum, and minimum values.

db.orders.insertMany( [ { _id: 0, name: "Pepperoni", size: "small", price: 19, quantity: 10, date: ISODate( "2021-03-13T08:14:30Z" ) }, { _id: 1, name: "Pepperoni", size: "medium", price: 20, quantity: 20, date : ISODate( "2021-03-13T09:13:24Z" ) }, { _id: 2, name: "Pepperoni", size: "large", price: 21, quantity: 30, date : ISODate( "2021-03-17T09:22:12Z" ) }, { _id: 3, name: "Cheese", size: "small", price: 12, quantity: 15, date : ISODate( "2021-03-13T11:21:39.736Z" ) }, { _id: 4, name: "Cheese", size: "medium", price: 13, quantity:50, date : ISODate( "2022-01-12T21:23:13.331Z" ) }, { _id: 5, name: "Cheese", size: "large", price: 14, quantity: 10, date : ISODate( "2022-01-12T05:08:13Z" ) }, { _id: 6, name: "Vegan", size: "small", price: 17, quantity: 10, date : ISODate( "2021-01-13T05:08:13Z" ) }, { _id: 7, name: "Vegan", size: "medium", price: 18, quantity: 10, date : ISODate( "2021-01-13T05:10:13Z" ) } ] )