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]
})

View

It is a read-only queryable object whose contents are defined by an aggregation pipeline on other collections or views.
It is computed when you read the view, and it is not stored to disk.

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

Compass

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

Mongodb

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