What is MongoDB?

MongoDB is a NoSQL document database that stores data in JSON-like BSON documents instead of tables.

SQL: Tables-> Rows -> Fixed Schema -> JOIN
MongoDB: Collections -> Collections -> Documents -> Flexible Schema -> $lookup

• A document is a JSON-like object stored inside a collection.

• A collection is a group of documents (similar to a table in SQL).

• Every MongoDB document has a unique _id field automatically generated.

• BSON is Binary JSON, the format MongoDB uses internally to store data.
  

MongoDB Queries :

1. db.users.find() -> Find all users

2. db.users.find({ age: 25 }) -> Find user by age

3. db.users.insertOne({ name: "Zahid",age: 28}) -> Insert document

4. db.users.updateOne({ name: "Zahid" }, { $set: { age: 29 } }) -> Update user

5. db.users.deleteOne({ name: "Zahid" }) -> Delete User