Mongodb

Description

MongoDB stores data records as BSON documents gathered in collections (= SQL table). BSON is a binary representation of JSON documents.
MongoDB documents are composed of field-and-value pairs. The value of a field can be any of the BSON data types.

var mydoc = { // field _id is a primary key _id: ObjectId("5099803df3f4948bd2f98391"), // name holds an embedded document that contains the fields first and last name: { first: "Alan", last: "Turing" }, birth: new Date('Jun 23, 1912'), death: new Date('Jun 07, 1954'), contribs: [ "Turing machine", "Turing test", "Turingery" ], views : NumberLong(1250000) }

Connect and authenticate

# connect mongosh mongodb://localhost:27017 # alias mongosh # connect and authenticate, use an environment variable to hide the password mongosh "mongodb://user:${DBPASSWORD}@<host>:<port>/admin?authSource=admin"

Authenticate

db.auth("username", "pwd") db.auth("username", passwordPrompt())

Database

// list the databases show dbs // switch to [dbname] use [dbname] // create a new database with a new collection (and insert data) use [newdbname] db.[newCollectionName].insertOne( { x: 1 } ) // drop the current database db.dropDatabase()

Collection

It gathers documents and is an equivalent of an SQL table.
A collection does not require its documents to have the same schema (the same set of fields and the same data types)

// list collections db.getCollectionInfos() db.runCommand('listCollections') db.createCollection("[collectionName]", { [option]: [value] })

Backup and restore

# restore the backup folder dump to the local mongodb instance mongorestore dump/

don't know what to do with file while restore

This may happen because the mongorestore command point to a backup sub-folder not to the backup folder itself.

Authentication

// list the users of the current database db.getUsers() db.runCommand('usersInfo') // get info of a specific user db.getUser("tom", { showCredentials: true, showPrivileges: true, showAuthenticationRestrictions: true }) // create admin use admin db.createUser( { user: "admin", pwd: "mypwd", roles: [ { role: "userAdminAnyDatabase", db: "admin" } ] } ) // create a user for the demo database use demo db.createUser( { user: "tom", pwd: passwordPrompt(), // or cleartext password roles: [ { role: "readWrite", db: "demo" }, { role: "read", db: "finances" } ] } ) // change password use admin db.changeUserPassword("tom", "secretpassword") db.changeUserPassword("tom", passwordPrompt()) // delete a user db.dropUser("tom")

/etc/mongod.conf

security: authorization: "enabled"

Bash

mongo <<EOF use admin db.auth("admin", "${MONGODBADMINPWD}") use mydb db.dropDatabase() EOF

Installation

Windows

choco install mongodb mongodb-shell

Key	Value
Service name	MongoDB
Data directory	C:\Program Files\MongoDB\Server\6.0\data\
Log directory	C:\Program Files\MongoDB\Server\6.0\log\

• Install the Database Tools in C:\Program Files\MongoDB\Tools

Archlinux

yay mongodb-bin # install dependencies mongodb-bin-debug, mongosh-bin, mongosh-bin-debug # GUI yay mongodb-compass # tools yay mongodb-tools # service sc-status mongodb.service