mongodb-helloworld

What is MongoDB?

https://docs.mongodb.com/ https://docs.mongodb.com/manual/mongo/ https://docs.mongodb.com/manual/tutorial/getting-started/

• MongoDB is a database solution

• Database server

• Popular for Read/Write heavy applications

• In MySQL there're tables but in MongoDB we have collections

• Inside of a collection there're Documents

• MongoDB is Schema-less

• Documents are in JSON(BSON) format (key value pairs)

    {
        "name": "Tanushka",
        "age": 25,
        "address":
        {
            "city": "Boralesgamuwa"
        },
        "hobbies": [
            {"name": "Gaming"},
            {"name": "Football"}
        ]
    }
  

• Key names should be in double quotations

• We can store nested data as shown by address (This allows to create complex relations between data and store them in one document and can be easily fetched without any complex joins)

• Hobbies are a list of embedded documents

APPLICATION----------------------------------------------------------------------------------->DATA

Frontend (UI) > Backend (Server)> Drivers(Node.js,Java, Python)<<< Queries >>> MongoDB Server << Communicate >> Storage Engine << File/Data Access >> DataBase files(Slow) || Memory(Fast)

BSON Data Structure

No schema (Gives a lot of flexibility) Less relations due to embedded documents Less collections (tables) no joins or merging required

MongoDB EcoSystem

MongoDB database

• Community/ Enterprise solutions
• Atlas (Cloud solution)
• Mobile
• Compass (GUI)
• BI connectors
• MongoDB charts

Stitch

• Serveless backend solution
• Serveless Query API
• Serveless Functions
• Database Triggers
• Real-Time Sync

Installing MongoDB

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

After installation add PATH variable of the MongoDB binaries C:\Program Files\MongoDB\Server\4.4\bin

Create data db path C:\data\db

Basic Commands

Run CMD as admin to stop the MongoDB background service in windows net stop MongoDB

To start the service mongod

To connect mongo

Clear screen cls

Show existing DB information show dbs

Create new DB (It will automatically switch to the newly created db) use dbname

Show current DB db

Insert document(MacBook Pro) to a collection(products) db.products.insertOne({"name": "MacBook Pro", "brand": apple, "price": 1099}) db.products.insertOne({"name": "iPhone 12", "brand": "apple", "price": 729, "processor": "A14", "features": { "os": "iOS 14.1", "ram": "4GB"}})

To view documents in a collection db.products.find() db.products.find().pretty()

To start the server in a different port mongod --port 27018 mongo --port 27018

To drop a database, load the database that needs to be dropped, use databaseName and then execute db.dropDatabase()

Drop a collection by, db.myCollection.drop()