mango DB installation Create Database, collections and Documents

 Database, Collection and Documents in MongoDB:

        Databases, collections, documents are important parts of MongoDB without them you are not able to store data on the MongoDB server. 

        A Database contains a collection, and a collection contains documents and the documents contain data in the form of key-value pair, they are related to each other.

Database

        In MongoDB, a database contains the collections of documents. One can create multiple databases on the MongoDB server. 

C:\Program Files\MongoDB\Server\5.0\data\

C:\Program Files\MongoDB\Server\5.0\log\

How to run monoDB? 

        first of all, set a path in environment variable the open 'CMD' and type mango --version then show any output like version imformation, so thats your mongodb is work. 

Start MongoDB

mongo

Show Database

It gives list of databases that are present in your MongoDB server. 

> show dbs
admin   0.000GB
config  0.000GB
local   0.000GB
>

create Database

>use database_name

        This command actually switches you to the new database if the given name does not exist and if the given name exists, then it will switch you to the existing database. Now at this stage, if you use the show command to see the database list, you will find that your new database is not present in that database list because, in MongoDB, the database is actually created when you start entering data in that database.

> use shreyashdb
switched to db shreyashdb

   [

  {
    "id":"1asd13k",
    "username": "shreyash kolhe",
    "email": "shreyashkolhe2001@gmail.com",
    "role":"develper"
  }
]

create collections

        Collections are just like tables in relational databases, they also store data, but in the form of documents. A single database is allowed to store multiple collections. As we know that MongoDB databases are schemaless, it is not necessary in a collection that the schema of one document is similar to another document. Or in other words, a single collection contains different types of documents. Create a collection to store documents.

> db.shreyashdb.insertOne({ name: "ReactJS", type:"Front End", blogpost:100, active:true})
{
        "acknowledged" : true,
        "insertedId" : ObjectId("61ca837682bfb31fe50836eb")
}
>

Document 

        In MongoDB, the data records are stored as BSON documents. Here, BSON stands for binary representation of JSON(JavaScript Object Notation) documents, although BSON contains more data types as compared to JSON. The document is created using key-value pairs and the value of the field can be of any BSON type.

check Current active DB

>db
shreyashdb

show collection inside DataBase

show collections

check how many documents in collection

> db.shreyashdb.find()
{ "_id" : ObjectId("61ca837682bfb31fe50836eb"), "name" : "ReactJS", "type" : "Front End", "blogpost" : 100, "active" : true }
>

> db.shreyashdb.find().pretty()
{
        "_id" : ObjectId("61ca837682bfb31fe50836eb"),
        "name" : "ReactJS",
        "type" : "Front End",
        "blogpost" : 100,
        "active" : true
}