Cheat Sheet

MongoDB Cheat Sheet

Bob Reselman
September 30, 2022
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About

MongoDB is a NoSQL, document-centric database for building highly available and scalable web applications. MongoDB makes it easy for developers to store, manage, and retrieve data when creating applications. 

This cheat sheet covers basic commands and tasks for using MongoDB. It introduces key concepts, like collections and indexes, and explains how to perform common tasks, including setting query results to a varable and using MongoDB’s aggregate method. It also provides tips on how to carefully execute dangerous tasks like dropping collections from a database.

Download the MongoDB Cheat Sheet and learn how to:

  • Access the Mongo shell
  • Navigate around Mongo
  • Create, delete, and list users in a database
  • Perform basic queries against a collection
  • Add, update, and remove documents
  • Use a variable to store query results
  • Work with indexes
  • Use aggregations in MongoDB

With Red Hat Developer cheat sheets, you get essential information right at your fingertips so you can work faster and smarter. Easily learn new technologies and coding concepts and quickly find the answers you need.

Excerpt

Working with a collection

A collection is an array of documents that exist within a given database. You can think of a document as a NoSQL record. 

The following sections show you how to create and delete a collection in a given database as well as how to list collections in a given database.

Create a collection

db.createCollection(<collection_name>)

Example:

> db.createCollection("pears")
{ "ok" : 1 }

Show all collections

show collections

Example:

> show collections
apples
oranges
pears

Delete a collection

db.<collection_name>.drop()

Example:

> db.pears.drop()
True

Working with documents

The following sections show you how perform basic queries against a given collection in a database.

Show all documents in a collection

db.<collection_name>.find()
db.["<collection_name>"].find()

Example:

> db["apples"].find()
"_id" : ObjectId("627d9053f7e6008a00844a81"), "type" : "granny smith",
"price" : 2.99, "countryOfOrigin" : "USA" }
{ "_id" : ObjectId("627d9053f7e6008a00844a82"), "type" : "golden
delicious", "price" : 0.99, "countryOfOrigin" : "Ireland" }
{ "_id" : ObjectId("627d9053f7e6008a00844a83"), "type" : "gala", "price" :
1.29, "countryOfOrigin" : "USA" }
{ "_id" : ObjectId("627d9053f7e6008a00844a84"), "type" : "empire",
"price" : 1.59, "countryOfOrigin" : "USA" }
{ "_id" : ObjectId("627d9053f7e6008a00844a85"), "type" : "delicious",
"price" : 1.59, "countryOfOrigin" : "USA" }
{ "_id" : ObjectId("627d9053f7e6008a00844a86"), "type" : "macintosh",
"price" : 0.99, "countryOfOrigin" : "USA" }
{ "_id" : ObjectId("627d9053f7e6008a00844a87"), "type" : "fuji", "price" :
0.99, "countryOfOrigin" : "Chile" }
{ "_id" : ObjectId("627d9053f7e6008a00844a88"), "type" : "golden
delicious", "price" : 0.99, "countryOfOrigin" : "Mexico" }
{ "_id" : ObjectId("627d9053f7e6008a00844a89"), "type" : "crab", "price" :
0.09, "countryOfOrigin" : "Canada" }

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