MongoDB Collection Creation and Document Insertion Quiz

RDBMS (Relational Database Management System)

• Stands for "Relational Database Management System"
• Enforced structured data model based on tables with predefined schemas
• Each table in a database schema has a unique name and defines the structure of the data it stores, including:
  • Data types of the data columns
  • Relationships between tables
  • Constraints
  • Primary keys
  • Foreign keys
• Fixed schema
• Need to alter the table structure if the schema changes, which is complex and time-consuming
• Cannot have dynamic fields on demand, i.e., add a field for specific records
• Scale up (Vertical scaling): relies on vertical scaling, adding more resources to a single server, which is expensive and not designed to be distributed
• Use centralized architecture

NoSQL Database

• Often interpreted as "Not Only SQL"
• A class of schema-less database system
• Allows dynamic data structures
• Horizontal scalability
• Distributes data across multiple servers to handle large volumes of data
• Supports different types of data models

NoSQL Types

• Key-value stores
• Graph database
• Document-oriented
• Column family

MongoDB

• An open-source, document-oriented database designed with scalability and developer agility in mind
• Stores data in JSON-like documents with dynamic schemas (schema-free, schema-less)
• Features:
  • Document-oriented database
  • Built-in horizontal scalability
  • High performance and indexing
  • Rich queries and data aggregations
  • Integration with various application frameworks
  • Large ecosystem and community

MongoDB vs RDBMS

• RDBMS has a fixed schema, while MongoDB has a dynamic schema
• RDBMS is best suited for complex queries, while MongoDB is not good for complex queries
• RDBMS is vertically scalable, while MongoDB is horizontally scalable

MongoDB Atlas

• A cloud database platform
• Easier to use than hosting a local database
• Allows for deployment of a database by setting up a free "Shared Cluster" and choosing a preferred cloud provider and region

MongoDB CRUD Operations

• Create: create or insert operations add new documents to a collection
• Read: retrieve documents from a collection
• Update: modify existing documents in a collection
• Delete: remove documents from a collection

MongoDB mongosh

• A way to interact with a MongoDB database
• Can be used to create a database, collection, and documents
• Can perform CRUD operations
• Can be used to query and manipulate data

Creating a Database and Collection

• Use the use command to create or switch to a database
• Use the createCollection() method to create a collection
• Alternatively, a collection can be created during the insert process

Inserting Documents

• Use the insertOne() method to insert a single document
• Use the insertMany() method to insert multiple documents
• Documents can be JSON objects

Querying Data

• Use the find() method to select data from a collection
• Use the findOne() method to select only one document
• Can use a query object to filter data
• Can use a projection object to specify which fields to include in the results

Updating Documents

• Use the updateOne() method to update the first document that matches the query
• Use the updateMany() method to update all documents that match the query
• Can use the upsert option to insert a document if it is not found

Deleting Documents

• Use the deleteOne() method to delete the first document that matches the query
• Use the deleteMany() method to delete all documents that match the query
• Can use the drop() method to remove a collection or view from the database### MongoDB Basics
• MongoDB is a NoSQL database that allows for dynamic schema changes.
• It uses a document-oriented data model, where each document is a JSON-like object with a dynamic schema.

MongoDB Query Language (MQL)

• MQL is based on a JSON-like syntax.
• Valid query expression formats:
  • { "key": value, … }
  • { "key": { "$selector": expression, … }, … }
  • { "$selector": expression, … }
  • { "$selector": [expression, …], … }
• Empty {} matches all documents.
• Each key-value pair in the query must be satisfied.

Query Selectors

• Comparison selectors:
  • $eq: values are equal
  • $ne: values are not equal
  • $gt: value is greater than another value
  • $gte: value is greater than or equal to another value
  • $lt: value is less than another value
  • $lte: value is less than or equal to another value
  • $in: value is matched within an array
• Logical selectors:
  • $and: returns documents where both queries match
  • $or: returns documents where either query matches
  • $nor: returns documents where both queries fail to match
  • $not: returns documents where the query does not match
• Evaluation selectors:
  • $regex: allows the use of regular expressions when evaluating field values
  • $text: performs a text search
  • $where: uses a JavaScript expression to match documents

Update Operators

• Fields:
  • $currentDate: sets the field value to the current date
  • $inc: increments the field value
  • $rename: renames the field
  • $set: sets the value of a field
  • $unset: removes the field from the document
• Arrays:
  • $addToSet: adds distinct elements to an array
  • $pop: removes the first or last element of an array
  • $pull: removes all elements from an array that match the query
  • $push: adds an element to an array

MongoDB Node.js Driver

• To use MongoDB with Node.js, you need to install the mongodb package.
• Import the MongoClient class: import { MongoClient } from 'mongodb';
• Connect to the database using the connection string: const client = new MongoClient(uri);
• Create a database and collection: const db = client.db('sample_mflix'); const collection = db.collection('movies');

CRUD Operations

• Create: insertOne() and insertMany() methods add new documents to a collection.
• Read: retrieve documents from a collection.
• Update: modify existing documents in a collection.
• Delete: remove documents from a collection.

MongoDB Atlas

• Create a cluster to deploy a database.
• Create a user and add IP addresses to the list of allowed IP addresses.
• Connect to the database using the MongoDB Shell (mongosh).
• Use the connection string provided by the MongoDB Atlas dashboard.

MongoDB Shell (mongosh)

• Install mongosh on your operating system.
• Verify the installation by typing mongosh in the terminal.
• Connect to the database using the connection string.
• Use the db command to see which database you are using.
• Use the show dbs command to see all available databases.
• Use the use command to change or create a new database.### MongoDB Basics
• MongoDB is a NoSQL database that allows for flexible schema design and scalable data storage.
• MongoDB provides a MongoDB Shell (mongosh) for interacting with the database.

Inserting Data

• db.posts.insertOne() method is used to insert a single document into a collection.
• db.posts.insertMany() method is used to insert multiple documents into a collection.
• If a collection does not exist, MongoDB will create it automatically when inserting documents.

Finding Data

• find() method is used to retrieve data from a collection.
• findOne() method is used to retrieve a single document from a collection.
• Both methods accept a query object to filter results.
• Projection is used to specify which fields to include in the results.

Updating Data

• updateOne() method is used to update a single document in a collection.
• updateMany() method is used to update multiple documents in a collection.
• The $set operator is used to update a field in a document.
• The $inc operator is used to increment a field in a document.

Deleting Data

• deleteOne() method is used to delete a single document from a collection.
• deleteMany() method is used to delete multiple documents from a collection.
• drop() method is used to delete a collection or view from the database.

Query Language

• MongoDB Query Language (MQL) is used for querying and manipulating data.
• MQL is based on a JSON-like syntax.
• Queries can be used to filter data using various operators, such as $gt, $lt, $eq, and $in.

Query Operators

• Comparison operators: $eq, $ne, $gt, $gte, $lt, $lte, and $in.
• Logical operators: $and, $or, and $nor.
• Evaluation operators: $regex and $text.

MongoDB Node.js Driver

• The MongoDB Node.js driver is used to interact with a MongoDB database in a Node.js application.
• The driver provides methods for inserting, finding, updating, and deleting data.
• The driver can be used to connect to a MongoDB Atlas database.

CRUD Operations

• Create: insertOne() and insertMany() methods.
• Read: find() and findOne() methods.
• Update: updateOne() and updateMany() methods.
• Delete: deleteOne() and deleteMany() methods.