Welcom to MongoDB World

• What is MongoDB
• What MongoDB can Manage
• NoSQL Databases
• NoSQL Behind History
• Basic Terminology
• Sample JSON Object
• MongoDB Default ID
• Advantages
• Where to use MongoDB?
• MongoDB Edition
• Install MongoDB
• MongoDB Data Modeling
• Embeded Data Model
• Normalized Data Model
• Data Type
• MongoDB Shell
• MongoDB Help
• MongoDB Statistics
• Show Database Names
• Create Database
• Show Collections in Database
• Drop Database
• Single Document Insert
• Multiple Documents Insert
• Find Single Document
• Find All Documents
• MongoDB Projection
• Projection
• Query Operators Usage
• Logical Operators
• Limit Records
• Sort Records
• Update One Document
• Update Documents
• Delete Document
• Beautify JSON Output

What is MongoDB

MongoDB is a cross-platform, document oriented database.

• Provides high performance
• High availability
• Easy scalability
• It is no SQL
• written in C++

What MongoDB can Manage

• Structured data
• Semi structured data
• Un structured data

NoSQL Databases

NoSQL Database is used to refer a non-SQL or non-relational database.

• No table
• No row
• No complex join

NoSQL Behind History

• In the early 1970, Flat File Systems are used, that time there was no standard, no format difficult to manage and share.
• In 1970 Computer scientist Edgar F. Codd proposed a database model to resolve this problem, known as relational database model
• But later relational database also get a problem that it could not handle big data, due to this problem there was a need of database which can handle every types of problems.
• The initial development of NoSQL database MongoDB began in 2007 by 10gen, the the company name changed with new name MongoDB Inc.
• Later in 2009, it is introduced in the market as an open source database server
• The first ready production of MongoDB has been considered from version 1.4 which was released in March 2010.

Basic Terminology

RDBMS	MongoDB
Database	Database
Table	Collection
Tuple/Row	Document
column	Field
Table Join	Embedded Documents
Primary Key	Primary Key (Default key _id provided by MongoDB itself)

Sample JSON Object

{
	_id: Objectld(7df78ad8902c) 
	title: 'value', 
	tags: ['value','value','value'],
	likes: 100, 
	comments: [
		{
			user: 'value' , 
			message: 'value', 
			dateCreated: new Date(2011,1,20,2,15), 
			like:0
		},
		{
			user: 'value' , 
			message: 'value' , 
			datecreated: new Date(2011,1,25,7,45),
			like:5
		}
	]
}

MongoDB Default ID

• As you see, in the example of a MongoDB document the _id field is called Object ID. MongoDB uses ObjectIds as the default value of _id field of each document, which is generated during the creation of any document.
• Object ID is treated as the primary key within any MongoDB collection. It is a unique identifier for each document or record. Syntax: ObjectId(<hexadecimal>).
• An ObjectId is a 12-byte BSON type hexadecimal string having the structure as shown in the example below. Example: ObjectId("6009c0eee65f6dce28fb3e50")
• The first 4 bytes are a timestamp value, representing the ObjectId’s creation, measured in seconds since the Unix epoch.
• Next 5-bytes represent a random value.

7df7	8ad	89	02c

• First 4 bytes = current timestamp
• Next 3 bytes = machine id
• Next 2 bytes = process id
• Last 3 bytes = incremental VALUE

Advantages

• Schema less
• single object
• No complex joins
• Deep query-ability
• Tuning
• Ease of scale-out
• Uses internal memory for storing

Where to use MongoDB?

• Big Data
• Content Management and Delivery
• Mobile and Social Infrastructure
• User Data Management
• Data Hub

MongoDB Edition

• MongoDB Community Server
• MongoDB Enterprise Server
• MongoDB Atlas

Install MongoDB

• Download MongoDB Community Server
• Install MongoDB Community Server on the local machine
• Download MongoDB Shell
• Extract Shell document
• cut mongosh file and pest it to C:\Program Files\MongoDB\Server\6.0\bin
• Download MongoDB Compass
• Install MongoDB Compass
• Connect MongoDB With Compass Application

MongoDB Data Modeling

MongoDB provides two types of data models

• Embedded Data Model
• Normalized Data Model

Embeded Data Model

In this model, you can have (embed) all the related data in a single document, it is also known as de-normalized data model.

{
	_id: ,
	Emp_ID: "10025AE556" 
	Personal_details : { 
		First_Name: "Radhika" , 
		Last_Name: "Sharma" , 
		Date_Of_Birth:"1995-09-26" 
	},
	Contact: { 
		e-mail: "radhika_sharma.123@gmail.com",
		phone : "9848622358",
	},
	Address:{
	city : "Hyderabad" , 
	Area : "Madapur" , 
	State: "Telangana" 
	}
}

Normalized Data Model

In this model, you can refer the sub documents in the original document.

Data Type

Data Types	Description
String	String is the most commonly used datatype. It is used to store data. A string must be UTF 8 valid in mongodb.
Integer	Integer is used to store the numeric value. It can be 32 bit or 64 bit depending on the server you are using.
Boolean	This datatype is used to store boolean values. It just shows YES/NO values.
Double	Double datatype stores floating point values.
Min/Max Keys	This datatype compare a value against the lowest and highest bson elements.
Arrays	This datatype is used to store a list or multiple values into a single key.
Object	Object datatype is used for embedded documents.
Null	It is used to store null values.
Symbol	It is generally used for languages that use a specific type.
Date	This datatype stores the current date or time in unix time format. It makes you possible to specify your own date time by creating object of date and pass the value of date, month, year into it.

MongoDB Shell

1. The mongo shell is similar to the mysql in MySQL, psql in PostgreSQL, and SQL*Plus in Oracle Database.
2. The mongo shell is an interactive JavaScript interface to MongoDB.
3. The mongo shell is included in the MongoDB installation by default.

	> Math.max(10,20,55,15)
	50
	> function Sum(num1,num2){
	...return num1+num2
	...}
	> sum(10,15)
	25

To see the list of command you need to use the help() function

• MongoDB Help

	db.help()

To get stats about MongoDB server, type the command db.stats() in MongoDB client. This will show the database name, number of collection and documents in the database.

• MongoDB Statistics

	db.stats()

• Show Database Names

	show dbs

Suppose we wantto create a database that doesn't exists at all. Then you have to to use database by a name and have to insert atleast one data belongs to that db's collection

• Create Database

	use schools
	db.students.insert({name:"Tanim",city:"Dhaka"})

• Show Collections in Database

	show collections

In Order to delete a database switch to that database then you can dropDatabase()

• Drop Database

	use schools
	db.dropDatabase()

If we want to create new collection belongs to an existing Database then you have to use createCollection() method

• Collection Create

	db.createCollection("teachers")

If requires to delete an existing collection use drop() method

• Drop Collection

	db.teachers.drop()

• Single Document Insert to a Collection

	db.students.insertOne({name:"Tahmid",city:"Dhaka"})

• Multiple Documents Insert to a Collection

	db.students.insertMany([{name:"Mehrab",city:"Donia"},{name:"Namita",city:"Comillah"},{name:"Hafiz",city:"Rajbari"}])

• Find Single Document

	db.students.findOne({name:"Namita"})

• Find All Documents

	db.studetns.find()

projection means selecting only the necessary data rather than selecting whole of the data of a document.

• MongoDB Projection

	db.students.find({},{_id:0,name:1})

Projection

• It shows the projected column.
• Projection uses boolean number.
• 0 for skip column & 1 for select column

• Query Operators

1. $eq : Equal To Operator
2. $lt : Less Than Operator
3. $lte : Less Than or Equal To Operator
4. $gt : Greater Than Operator
5. $gte : Greater Than or Equal To Operator
6. $ne : Not Equal To Operator
7. $in : In Operator
8. $nin : Not In Operator

• Query Operators Usage

db.Products.find({price:{$eq:"1000"}})  
db.Products.find({price:{$lt:"1000"}})  
db.Products.find({price:{$lte:"1000"}})  
db.Products.find({price:{$gt:"1000"}})  
db.Products.find({price:{$gte:"1000"}})  
db.Products.find({price:{$ne:"1000"}}) 
db.Products.find({price:{$in:["100","200","3000"]}},{price:1})
db.Products.find({price:{$nin:["100","200","3000"]}},{price:1})

• Logical Operators

1. $and : Logical AND Opeartor
2. $or : Logical OR Operator

	db.products.find({$and:[{price:{$eq:"100"}},{special_price:{$eq:"NA"}}]},{price:1,special_price:1,category:1})

	db.products.find({$or:[{price:{$eq:"100"}},{special_price:{$eq:"NA"}}]},{price:1,special_price:1,category:1})

To Select Specific number of records use limit method

• Limit Records

	db.students.find().limit(5)

• Sort Records

(Ascending: 1, Descending: -1)

	db.students.find().sort({name:1,city:-1})
	db.products.find({},{name:1}).sort({name:-1})

• Update One Document

	db.students.updateOne({id:100,{$set:{name:"Anwar",city:"Dhaka"}}})

• Update Documents

db.COLLECTION_NAME.update(SELECTION_CRITERIA, UPDATED_DATA)

	db.students.update({id:100},{$set:{name:"Jahid",city:"Dhaka"}})

• Delete Document

	db.students.remove({name:"Jahid",city:"Dhaka"})

• Beautify JSON Output

pretty()

	db.students.find().pretty()