MongoDB Cheat Sheet

Maxime BeugnetPublished Jan 31, 2022 • Updated Jan 26, 2023

MongoDB

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First steps in the MongoDB World? This cheat sheet is filled with some handy tips, commands, and quick references to get you connected and CRUD'ing in no time!

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Connect MongoDB Shell
Helpers
CRUD
Databases and Collections
Indexes
Handy commands
Change Streams
Replica Set
Sharded Cluster
Wrap-up

Connect MongoDB Shell

Code Snippet

More documentation about the MongoDB Shell.
To connect with the new mongosh, just replace mongo by mongosh.

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Helpers

Show Databases

Code Snippet

Switch Database

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Show Collections

Code Snippet

Run JavaScript File

Code Snippet

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CRUD

Create

Code Snippet

Read

Code Snippet

db.coll.findOne() // returns a single document
db.coll.find()    // returns a cursor - show 20 results - "it" to display more
db.coll.find().pretty()
db.coll.find({name: "Max", age: 32}) // implicit logical "AND".
db.coll.find({date: ISODate("2020-09-25T13:57:17.180Z")})
db.coll.find({name: "Max", age: 32}).explain("executionStats") // or "queryPlanner" or "allPlansExecution"
db.coll.distinct("name")

// Count
db.coll.count({age: 32})          // estimation based on collection metadata
db.coll.estimatedDocumentCount()  // estimation based on collection metadata
db.coll.countDocuments({age: 32}) // alias for an aggregation pipeline - accurate count

// Comparison
db.coll.find({"year": {$gt: 1970}})
db.coll.find({"year": {$gte: 1970}})
db.coll.find({"year": {$lt: 1970}})
db.coll.find({"year": {$lte: 1970}})
db.coll.find({"year": {$ne: 1970}})
db.coll.find({"year": {$in: [1958, 1959]}})
db.coll.find({"year": {$nin: [1958, 1959]}})

// Logical
db.coll.find({name:{$not: {$eq: "Max"}}})
db.coll.find({$or: [{"year" : 1958}, {"year" : 1959}]})
db.coll.find({$nor: [{price: 1.99}, {sale: true}]})
db.coll.find({
  $and: [
    {$or: [{qty: {$lt :10}}, {qty :{$gt: 50}}]},
    {$or: [{sale: true}, {price: {$lt: 5 }}]}
  ]
})

// Element
db.coll.find({name: {$exists: true}})
db.coll.find({"zipCode": {$type: 2 }})
db.coll.find({"zipCode": {$type: "string"}})

// Aggregation Pipeline
db.coll.aggregate([
  {$match: {status: "A"}},
  {$group: {_id: "$cust_id", total: {$sum: "$amount"}}},
  {$sort: {total: -1}}
])

// Text search with a "text" index
db.coll.find({$text: {$search: "cake"}}, {score: {$meta: "textScore"}}).sort({score: {$meta: "textScore"}})

// Regex
db.coll.find({name: /^Max/})   // regex: starts by letter "M"
db.coll.find({name: /^Max$/i}) // regex case insensitive

// Array
db.coll.find({tags: {$all: ["Realm", "Charts"]}})
db.coll.find({field: {$size: 2}}) // impossible to index - prefer storing the size of the array & update it
db.coll.find({results: {$elemMatch: {product: "xyz", score: {$gte: 8}}}})

// Projections
db.coll.find({"x": 1}, {"actors": 1})               // actors + _id
db.coll.find({"x": 1}, {"actors": 1, "_id": 0})     // actors
db.coll.find({"x": 1}, {"actors": 0, "summary": 0}) // all but "actors" and "summary"

// Sort, skip, limit
db.coll.find({}).sort({"year": 1, "rating": -1}).skip(10).limit(3)

// Read Concern
db.coll.find().readConcern("majority")

Update

Code Snippet

db.coll.update({"_id": 1}, {"year": 2016}) // WARNING! Replaces the entire document
db.coll.update({"_id": 1}, {$set: {"year": 2016, name: "Max"}})
db.coll.update({"_id": 1}, {$unset: {"year": 1}})
db.coll.update({"_id": 1}, {$rename: {"year": "date"} })
db.coll.update({"_id": 1}, {$inc: {"year": 5}})
db.coll.update({"_id": 1}, {$mul: {price: NumberDecimal("1.25"), qty: 2}})
db.coll.update({"_id": 1}, {$min: {"imdb": 5}})
db.coll.update({"_id": 1}, {$max: {"imdb": 8}})
db.coll.update({"_id": 1}, {$currentDate: {"lastModified": true}})
db.coll.update({"_id": 1}, {$currentDate: {"lastModified": {$type: "timestamp"}}})

// Array
db.coll.update({"_id": 1}, {$push :{"array": 1}})
db.coll.update({"_id": 1}, {$pull :{"array": 1}})
db.coll.update({"_id": 1}, {$addToSet :{"array": 2}})
db.coll.update({"_id": 1}, {$pop: {"array": 1}})  // last element
db.coll.update({"_id": 1}, {$pop: {"array": -1}}) // first element
db.coll.update({"_id": 1}, {$pullAll: {"array" :[3, 4, 5]}})
db.coll.update({"_id": 1}, {$push: {scores: {$each: [90, 92, 85]}}})
db.coll.updateOne({"_id": 1, "grades": 80}, {$set: {"grades.$": 82}})
db.coll.updateMany({}, {$inc: {"grades.$[]": 10}})
db.coll.update({}, {$set: {"grades.$[element]": 100}}, {multi: true, arrayFilters: [{"element": {$gte: 100}}]})

// Update many
db.coll.update({"year": 1999}, {$set: {"decade": "90's"}}, {"multi":true})
db.coll.updateMany({"year": 1999}, {$set: {"decade": "90's"}})

// FindOneAndUpdate
db.coll.findOneAndUpdate({"name": "Max"}, {$inc: {"points": 5}}, {returnNewDocument: true})

// Upsert
db.coll.update({"_id": 1}, {$set: {item: "apple"}, $setOnInsert: {defaultQty: 100}}, {upsert: true})

// Replace
db.coll.replaceOne({"name": "Max"}, {"firstname": "Maxime", "surname": "Beugnet"})

// Save
db.coll.save({"item": "book", "qty": 40})

// Write concern
db.coll.update({}, {$set: {"x": 1}}, {"writeConcern": {"w": "majority", "wtimeout": 5000}})

Delete

Code Snippet

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Databases and Collections

Drop

Code Snippet

Create Collection

Code Snippet

Other Collection Functions

Code Snippet

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Indexes

List Indexes

Code Snippet

Create Indexes

Code Snippet

Drop Indexes

Code Snippet

Hide/Unhide Indexes

Code Snippet

Indexes documentation

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Handy commands

Code Snippet

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Change Streams

Code Snippet

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Replica Set

Code Snippet

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Sharded Cluster

Code Snippet

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Wrap-up

I hope you liked my little but - hopefully - helpful cheat sheet. Of course, this list isn't exhaustive at all. There are a lot more commands but I'm sure you will find them in the MongoDB documentation.

If you feel like I forgot a critical command in this list, please send me a tweet and I will make sure to fix it.

Check out our free courses on MongoDB University if you are not too sure what some of the above commands are doing.

If you have questions, please head to our developer community website where the MongoDB engineers and the MongoDB community will help you build your next big idea with MongoDB.

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Table of Contents
Connect MongoDB Shell
Helpers
CRUD
Databases and Collections
Indexes
Handy commands
Change Streams
Replica Set
Sharded Cluster
Wrap-up

MongoDB

MongoDB Cheat Sheet

Table of Contents

Connect MongoDB Shell

Helpers

Show Databases

Switch Database

Show Collections

Run JavaScript File

CRUD

Create

Read

Update

Delete

Databases and Collections

Drop

Create Collection

Other Collection Functions

Indexes

List Indexes

Create Indexes

Drop Indexes

Hide/Unhide Indexes

Handy commands

Change Streams

Replica Set

Sharded Cluster

Wrap-up

Related

Integrating MongoDB with Amazon Managed Streaming for Apache Kafka (MSK)

Mapping Terms and Concepts from SQL to MongoDB

A Summary of Schema Design Anti-Patterns and How to Spot Them

Three Underused MongoDB Features

Table of Contents