MongoDB

Initial Concepts

Basic CRUD, Projection, Embedded/Nested Documents, Array

Schema & Relations

Exploring The Shell and The Server

Create/Insert, Write concern, Atomicity

Read

Update

Delete

Index and others

Geospatial Data

Aggregation Framework

Numeric Data

Security

Performance Fault Tolerancy Deployment

Transactions

SKIPPED

• Shell to drive
• Introducing Stitch

Initial Concepts

💡 MongoDB names came from **humongous** as it can **store** lots and **lots of data**.

• Store data as documents like JavaScript Object
• noSQL database
• Store like JSON
• BSON (b ⇒ binary) Data Structure into server
• No schema(can add if wanted)
• No / few relations
• Flow of data
  • Database
  • Collection(Like table)
  • Document(like JSON object values these are schemaless

Normalizing: Storing and distributing data in multiple tables where every table has a clear schema and use lots of relations(in SQL).

As MongoDB saves all in one single document so for fetching it does not need any complex operation like join(SQL) so MongoDB can fetch query is more simple, more flexible, and more efficient(as no need to merge collection/table) than SQL.

MongoDB is popular for read and write heavy applications (like sensors which send data every second/online shop/blog).

Some very basic commands

Start MongoDB on the shell

mongo

Show all databases(admin, config, and local are predefined there)

show dbs

Use existing database or create a new one

Will connected with database name 'shop' if already exits or if the database is not exited yet MongoDB will create that

use shop

Output will be

switched to db shop

Note: If the database is not created previously this command will create that database but the shop database will not create instantly(as a result show dbs will not list shop db). When we will first add data to the shops database than MongoDB implicitly will create that database and also show dbs commands that will list the database.

Get all documents of a collection.

Will give all data as we add not add any argument.

db.products.find()

Get JSON like format

Will return exactly the same data as JSON like format which is easy to read.

db.products.find().pretty

Clear the screen

cls

MongoDB Ecosystem

MongoDB Database

1. Self - Managed / Enterprise
   1. CloudManager / OpsManager
2. Atlas(Cloud)
3. Mobile

Others options

1. Compass
2. BI Connectors
3. MongoDB Charts

Stitch

💡 Basically a serverless backend solution.

That gives

💡 **Serverless Query Api** **⇒** a tool sets or tools to directly database query from inside client apps. 💡 **Serverless Functions(in the cloud ⇒ related to js) ⇒** a tool sets or tools to directly database query from inside client apps. 💡 **Database Triggers ⇒** that allows us to events in a database, like a document was inserted and then execute a function in response to that and that function could then maybe send an e-mail. 💡 **Real-Time Sync ⇒** basically is built to synchronize a database in a cloud with that mobile offline supporting database.

How MongoDB works

Application

• Frontend(UI)
• Backend(Server) ⇒ Which interacts/communicates with MongoDB server using their corresponding drivers
  • Node.js
  • Java
  • Python
  • MongoDB Shell(does not depends on any specific programming language).

Data

• MongoDB server
  • MongoDB server use a storage engine default for MongoDB is Wired Tiger. Which access file/data where the data kept(database information collection, table, etc)
    • Storage Engine
      • Read + Write Data to Files(slow)
      • Read + Write Data in Memory(fast) ⇒ Memory(RAM)

Documents Created Implicity

JSON data converts into BSON data

{ "name" : "MAX", "age" : 29 }

it converts into BSON

BSON

1. Binary data
2. Extends JSON Types(e.g more detailed Number Types)
3. Efficient Storage

MongoD service

💡 **mongod** stands for “**Mongo Daemon**”. mongod is a **background process** used by MongoDB. The main purpose of mongod is to manage all the MongoDB server tasks. For instance, accepting requests, responding to clients, and memory management.

mongo is a command line shell that can interact with the client (for example, system administrators and developers).

Start mongod process(default port is 27017)

sudo mongod => To start in default port
sudo mongod --port 27018 => can use if in any case default port 27017 not available 

Start MongoDB on the server

mongo => to start in default port 27017
mongo --port 27018 => to start at 27018 port