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MongoDB Basics

MongoDB database basics​

{
   _id: Object("765uhgsld9900dc"),
   name: "Sam",
   age: 99,
}
 {
   _id: Object("560wzlsse2910pb"),
   name: "John",
   age: 32,
}

  • mongo: mongo is the command-line shell that connect to a specific instance of mongod
  • mongod: This is the primary daemon process for the MongoDB system
  • mongos: sharded cluster
  • mongosh: Mongodb shell is a fully functional javascript and node.js REPL environment

mongosh commands​

connect through docker bash​

docker exec -it [container-name] bash

launch mongo shell mongosh​

mongosh -u [user-name] -p [password]

Passing environmental variable to docker

docker run -d --network some-network --name some-mongo \
	-e MONGO_INITDB_ROOT_USERNAME=mongoadmin \
	-e MONGO_INITDB_ROOT_PASSWORD=secret \
	mongo
docker run -it --rm --network some-network mongo \
	mongosh --host some-mongo \
		-u mongoadmin \
		-p secret \
		--authenticationDatabase admin \
		some-db

Basic commands

list all the databases​

show dbs

create database​

This command will create the database if it doesn't exist and switch to that database

use [database-name]

drop database​

Switch to the database and execute the command below

db.dropDatabase()

create collection and insert document​

collection name is visitor and has document with name and age as fields

db.visitor.insertOne({"name":"sam", "age":23})

switching to secopsdb and creating visitor collection with data in it.

test> use secopsdb
switched to db secopsdb
schooldb> db.visitor.insertOne({"name":"sam", "age":23})

create collection with validator​

This command creates a collection secopsuser with required fields name and age in the document

secopsdb> db.createCollection("secopsuser", {validator:{$jsonSchema:{bsonType:"object", required:["name","age"], properties:{name:{bsonType:"string", description:"Must be a String and is required"}, age:{bsonType:"int", description:"Must be an Integer and is required"},}}}})

list all the collections​

show collections

get detailed information of collection​

db.getCollectionInfos({name:"secopsuser"})

drop the colleciton​

This command will drop the collection visitor

db.visitor.drop()

insert One user into the collection​

db.secopsuser.insertOne({name:"johnny",age:45})

insert Many user into the collection​

db.secopsuser.insertMany([{name:"jack",age:22},{name:"sammy",age:39}])

list all documents in the collection​

db.secopsuser.find()

list only 2 documents​

db.secopsuser.find().limit(2)

find document with field name has john​

db.secopsuser.find({name:"john"})

update a document​

updates the document with field name containing john to John Smith

db.secopsuser.updateOne({name:"john"}, {$set:{name:"John Smith"}})

delete One document​

db.secopsuser.deleteOne({name:"sammy"})

delete Many documents​

deletes all the documents with fields with age 25

db.secopsuser.deleteMany({age:25})

User management​

Authorization and roles management

Create user​

db.createUser({user:"bond",pwd:"123456", roles:[{role:"read",db:"secopsdb"}]})

Create Admin user​

db.createUser({user:"superbond",pwd:"123456", roles:["root"]})

list users​

show users

delete user​

db.dropUser("bond")

Enable Authorization​

Update the authorization option enabled in the mongod conf file

security:
  authorization: enabled

Authenticate User access db​

mongosh --port 27017 --authenticateDatabase "secopsdb" -u "bond" -p "123456"