Points of MongoDb

NoSQL database

MongoDb is a NoSQL database which is much more agile and flexible than relational databases.

NoSQL vs SQL:

• Agile and flexible: schema is not required, and easy to change. Which usually cause better performance
• Ability to scale-out (distribute the load among multiple servers)
• To handle large volumes of structured, semi-structured, and unstructured data

Ref: SQL vs NoSQL: The Differences

Terminologies

Document: MongoDb stores data as BSON documents
Collection: analogous to an SQL table, to store a collection of documents

CRUD

Create

SQL

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INSERT INTO book (
  `ISBN`, `title`, `author`
)
VALUES (
  '9780992461256', 
  'Full Stack JavaScript', 
  'Colin Ihrig & Adam Bretz'
);

MongoDb

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db.book.insert({
  ISBN: "9780992461256",
  title: "Full Stack JavaScript",
  author: "Colin Ihrig & Adam Bretz"
});

Read

SQL

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SELECT title FROM book
WHERE price > 10;

MongoDb

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db.book.find(
  { price: { >: 10 } },
  { _id: 0, title: 1 }
);

Update

SQL

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UPDATE book
SET price = 19.99
WHERE ISBN = '9780992461256'

MongoDb

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db.book.update(
  { ISBN: '9780992461256' },
  { $set: { price: 19.99 } }
);

Delete

SQL

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DELETE FROM book
WHERE publisher_id = 'SP001';

MongoDb

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db.book.remove({
  "publisher.name": "SitePoint"
});