Database Configuration

Relevant source files

The following files were used as context for generating this wiki page:

• BACKEND/src/db/index.js
• BACKEND/src/index.js
• BACKEND/src/models/User.model.js
• BACKEND/package.json
• BACKEND/src/constants.js

Introduction

The database configuration system in the EICHackathon project provides a robust interface for connecting the Node.js backend to a MongoDB instance. It utilizes the Mongoose Object Data Modeling (ODM) library to manage data relationships, provide schema validation, and facilitate object-document mapping. The primary goal of this module is to ensure a stable, asynchronous connection to the database before the Express server begins handling requests.

The configuration relies on environment variables for sensitive connection details and follows a modular pattern, separating connection logic from data modeling. This structure supports secure authentication and efficient data persistence for features such as user management.
Sources: BACKEND/src/db/index.js, BACKEND/src/index.js, BACKEND/package.json:28

Connection Architecture

The database connection is established through a dedicated utility function that leverages environment variables and Mongoose. The system ensures that the application does not start listening for HTTP traffic until a successful database handshake is confirmed.

Initialization Workflow

The server entry point initializes the database connection by calling the connectDB function. Upon a successful promise resolution, the Express application starts. If the connection fails, the process is terminated with an exit code of 1 to prevent the application from running in a broken state.

The diagram shows the sequential dependency between database connectivity and server availability.
Sources: BACKEND/src/index.js:13-23, BACKEND/src/db/index.js:4-15

Configuration Parameters

The connection logic utilizes specific constants and environment variables to target the correct database instance and collection.

Variable	Source	Purpose
process.env.URL	.env	The MongoDB connection string (URI).
DB_NAME	src/constants.js	The specific name of the database to use.
process.env.PORT	.env	Port on which the server listens after DB connection.

Sources: BACKEND/src/db/index.js:5-8, BACKEND/src/index.js:15

Data Modeling

The project uses Mongoose schemas to define the structure of documents within the MongoDB collections. Currently, the system implements a robust User model with built-in security features.

User Schema Implementation

The User model defines the attributes and behaviors for application users. It includes validation, indexing for performance, and middleware for security.

Field	Type	Constraints	Description
username	String	Unique, Required, Indexed, Lowercase	Unique identifier for user login.
email	String	Unique, Required, Lowercase	User contact and auth email.
fullName	String	Required, Indexed	The user's display name.
password	String	Required	Bcrypt hashed password string.
refreshToken	String	Optional	Token for session persistence.

Sources: BACKEND/src/models/User.model.js:5-35

Security Logic and Middleware

The database configuration includes pre-save hooks and instance methods to handle encryption and authentication tokens.

• Pre-save Hook: Automatically hashes the user's password using bcrypt (10 rounds) before saving to the database, provided the password field was modified.
• Password Verification: An instance method isPasswordCorrect provides a secure way to compare plain-text inputs with stored hashes.
• JWT Generation: Methods are provided to generate Access and Refresh tokens using jsonwebtoken.

The sequence diagram illustrates the automated security processing that occurs during document persistence.
Sources: BACKEND/src/models/User.model.js:38-76

Implementation Details

The core connection logic is encapsulated in BACKEND/src/db/index.js.

const connectDB = async () => {
  try {
    const connectionInstance = await mongoose.connect(`${process.env.URL}`, {
      dbName: DB_NAME,
    });
    console.log(
      `\n MongoDB connected !! DB_HOST: ${connectionInstance.connection.host}`
    );
  } catch (error) {
    console.log("MONGODB CONNECTION ERROR", error);
    process.exit(1);
  }
};

Sources: BACKEND/src/db/index.js:4-15

Summary

The Database Configuration module establishes a critical foundation for the EICHackathon backend. By enforcing a "Database-First" startup policy, it prevents runtime errors related to data persistence. Through the use of Mongoose schemas and bcrypt-integrated middleware, it ensures that data is not only structured but also secure by default.