MongoDB Cheatsheet

View all database

> show dbs

Create new database

> use [Database name]

View current database

> db

Delete database

> db.dropDatabase()

Switch to a database

> use [Database name]

Show collections

> show collections

Create a collection named myCollection

> db.createCollection('myCollection')

Drop or delete a collection named myCollection

> db.myCollection.drop()

Insert data into MongoDB collection

> db.COLLECTION_NAME.insert(document)

Example

> db.myCollection.insert({
... ... 'name': 'Rwitesh',
... ... 'lang': 'Java',
... ... 'id': 1
... ... })
WriteResult({ "nInserted" : 1 })

Here myCollection is the name of the collection.

[NOTE] You can use db.myCollection.insertOne(document), if you want to add only one document.

Insert array of documents into MongoDB collection

> db.COLLECTION_NAME.insertMany([Store documents as array objects])

Example

Here geeks is a collection in which I have stored documents.

> db.geeks.insertMany([
... {
... First_Name : "Rwitesh",
... Last_Name : "Bera",
... Phone : "9876543210",
... id : 1
... },
... {
... First_Name : "Alistair",
... Last_Name : "Hey",
... Phone : "9080706050",
... id : 2
... },
... {
... First_Name : "Alex",
... Last_Name : "Ciro",
... Phone : "9192939495",
... id : 3
... }
... ])

Find/ Query document from MongoDB collection

> db.COLLECTION_NAME.find()

Example

> db.geeks.find()
{ "_id" : ObjectId("6100483bb398f4a34021554b"), "First_Name" : "Rwitesh", "Last_Name" : "Bera", "Phone" : "9876543210", "id" : 1 }
{ "_id" : ObjectId("6100483bb398f4a34021554c"), "First_Name" : "Alistair", "Last_Name" : "Hey", "Phone" : "9080706050", "id" : 2 }
{ "_id" : ObjectId("6100483bb398f4a34021554d"), "First_Name" : "Alex", "Last_Name" : "Ciro", "Phone" : "9192939495", "id" : 3 }

Display the results in formatted way

> db.COLLECTION_NAME.find().pretty()

Search in Database

Example

> db.geeks.find({"id" : 1})
{ "_id" : ObjectId("6100483bb398f4a34021554b"), "First_Name" : "Rwitesh", "Last_Name" : "Bera", "Phone" : "9876543210", "id" : 1 }

Count the number of documents

Example

> db.geeks.count()
3

Delete a document

> db.COLLECTION_NAME.remove(DELLETION_CRITTERIA)

It will delete the document which has the given criteria.

Example

> db.geeks.remove({"First_Name" : "Rwitesh"})
WriteResult({ "nRemoved" : 1 })

If you don't specify any criteria, then MongoDB will delete the entire documents from the collection.

> db.geeks.remove({})

Limit() Methods

Limit method accepts one number argument, which is the number of documents you want to be displayed.

> db.COLLECTION_NAME.find().limit(NUMBER)

Skip() Method

Skip method accepts one number argument and is used to skip the number of documents.

> db.COLLECTION_NAME.find().limit(NUMBER).skip(NUMBER)

Sort() Method

Sort method is used to display documents in sorting order. Make sure that your each document has one key value.

Ascending Order

> db.COLLECTION_NAME.find().sort({KEY:1})

Descending Order

> db.COLLECTION_NAME.find().sort({KEY:-1})

Update a field in document

> db.COLLECTION_NAME.update(SELECTION_CRITERIA, UPDATED_DATA)

Example

Updating the id here

> db.geeks.update({"First_Name" : "Rwitesh"}, 
... { 
... "First_Name" : "Rwitesh",
... "Last_Name" : "Bera",
... "Phone" : "9876543210",
... "id" : 999 
... })