MongoDB

• MongoDB is a document database designed for ease of development and scaling.
• It is intuitive and easy-to-use NoSQL database.
• Available as community and enterprise edition.
• The community edition itself is very powerful

Mongo vs MongoD

1. Mongo -> It is the command-line shell that connects to a specific instance of MongoD.
2. MongoD -> It is “Mongo Daemon” it’s basically the host process for the database.

Terminologies

SQL Terminologies — -> MongoDB Terminologies Database — -> Database Table — -> Collections (JS Objects) Rows — -> Documents (BSON) Columns — -> Fields

• BSON is more efficient than JSON

Example:

{
    name: "smitpatel",
    age: 25,
    status: "A",
    groups: ["news", "sports"]
}
This is knows as "field:value" pair

Installation

Download MongoDB community server for respective OS, from internet

https://www.mongodb.com/try/download/community

• Install it as a service, don’t forget to add it in environment variables
• MongoDB Compass -> It is basically a GUI version of the database
• Capped Collection will keep deleting older data

Usage

Databases

View All Databases

show dbs;

Creating or switching a database

use <database_name>

Verify the database name

db;

Delete/Drop Database

show dbs;
use <db_name>;
db;
db.dropDatabase();

Collections

To View Collections

show collections;

Create a new Collection

db.createCollection('name');

Delete a Collection

db.<collection name>.drop();

Documents/Rows

Insert a row in collection

db.<collection_name>.insert({
    'name': 'Smit',
    'age': 20,
    'skills': ["mongo", "express", "next", "node", "python", "machinelearning"]
})

Insert multiple rows in a collection

db.<collection_name>.insertMany([
    {
        "name": "SMIT",
        "age": 21,
        "skills": ["python", "flask"]
    },
    {
        "name": "PATEL",
        "age": 21,
        "skills": ["devops", "cloud"]
    }
]);

Object Id will be returned, it acts like primary key

Show rows in a collection

db.<collection_name>.find();

            or
        we can also prettify it

db.<collection_name>.find().pretty();

Search

Search for a particular details

db.<collection_name>.find({"age": 20})

Limit the outputs to be displayed

db.<collection_name>.find({"age": 20}).limit(3);

Will only display 3 results at max

Count the number of rows in the output

db.<collection_name>.find().count();

Sorting ascending/descending

db.<collection_name>.find().sort({age:1}).prety(); //sorting in ascending order
db.<collection_name>.find().sort({age:-1}).pretty(); //sorting in descending order

Find one row

db.<collection_name>.findOne({name: "Smitpatel"}); //will terminate as soon as first instance is found

Updating the database

Update a row

db.<collection_name>.update({name: "MSDHONI"}, <New Object>);

Insert a row, if no matches found

db.<collection_name>.update(<search_param>, <New Object>, {upsert: true});

Delete a row

db.<collection_name>.remove(<search_param>);

Increment operator

db.<collection_name>.update(
    <search_param>, 
    {
        $inc:{
            member_since: 2
        }
    }
);

Rename operator

db.<collection_name>.update(
    <search_param>,
    {
        $rename:{
            member_since: "member"
        }
    }
)

Less than operator / Greater than / less than equals / greater than equals

db.<collection_name>.find({member_since: {$lt: 90}});
db.<collection_name>.find({member_since: {$gt: 10}});
db.<collection_name>.find({member_since: {$lte: 90}});
db.<collection_name>.find({member_since: {$gte: 10}});

MongoDB Atlas

• Atlas is basically database on cloud. {WE CAN USE HYBRID}
• It offers multiple features
• We can also give access to specific user as well
• The access can also be temporary, but it fast, reliable, and easy to use compared to others.
• I always prefer Monogo cloud
• Can be connected via MongoDB Compass or via code as well.