mongo-aggregate-example

How to use aggregation in MongoDB

Link บทความ : ทดลองเขียน Aggregation ใน MongoDB

Datasheet

• zipcodes collection

Usage

npm install
npm start

What is Aggregation Pipeline?

• A series of document transformations
• Executed in stages
• $match => $project => $group => $sort

Operators

• $match : Filter documents
• $project : Reshape documents (Include, exclude, rename fields)
• $group : Summarize documents
• $sort : Ordering documents
• $limit : Paginate documents
• $skip : Same as $limit

SQL to Aggregation Mapping

• SELECT = $project
• WHERE = $match
• ORDER BY = $sort
• LIMIT = $limit

Reference : SQL to Aggretation Mapping Chart