MongoDB Cheat Sheet

Database Operations:

        
// Create a database
use database_name

// Show available databases
show databases

// Switch to a different database
use database_name

// Drop a database
db.dropDatabase()
        
    

Collection Operations:

        
// Create a collection
db.createCollection("collection_name")

// Show available collections
show collections

// Drop a collection
db.collection_name.drop()
        
    

Document Operations:

        
// Insert a document
db.collection_name.insertOne({key1: value1, key2: value2})

// Insert multiple documents
db.collection_name.insertMany([{key1: value1, key2: value2}, {key1: value3, key2: value4}])

// Find documents
db.collection_name.find({key: value})

// Find documents with specific criteria
db.collection_name.find({$or: [{key1: value1}, {key2: value2}]})

// Update a document
db.collection_name.updateOne({key: value}, {$set: {new_key: new_value}})

// Update multiple documents
db.collection_name.updateMany({key: value}, {$set: {new_key: new_value}})

// Delete a document
db.collection_name.deleteOne({key: value})

// Delete multiple documents
db.collection_name.deleteMany({key: value})
        
    

Query Operators:

        
// Comparison operators
$eq: equal to
$ne: not equal to
$gt: greater than
$gte: greater than or equal to
$lt: less than
$lte: less than or equal to

// Logical operators
$and: logical AND
$or: logical OR
$not: logical NOT

// Element operators
$exists: checks if a field exists
$type: checks the data type of a field

// Array operators
$in: matches any value in an array
$nin: does not match any value in an array
$all: matches arrays that contain all the specified elements

// Regular expression operators
$regex: matches documents that satisfy a regular expression

// Projection operators
$project: includes or excludes fields from the result
        
    

Indexing:

        
// Create an index
db.collection_name.createIndex({key: 1})

// List all indexes
db.collection_name.getIndexes()

// Drop an index
db.collection_name.dropIndex({key: 1})
        
    

Aggregation:

        
// Aggregation pipeline stages
$match: filters documents based on specified criteria
$group: groups documents by specified keys and performs calculations
$project: shapes the documents' fields
$sort: sorts documents based on specified criteria
$limit: limits the number of documents in the output
$skip: skips a specified number of documents in the output
$lookup: performs a left outer join on two collections
$unwind: deconstructs an array field into multiple documents