Documenting project requirements and designing a database

Documenting project requirements and designing a database properly are crucial steps for a developer to ensure smooth development, scalability, and maintainability. Below is a structured approach to handling both:

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1. Project Requirement Documentation

A. Define Project Scope

• Briefly explain the purpose of the project.
• Identify key objectives and goals.
• Specify the target users and their needs.

B. Identify Stakeholders

• List all involved parties (e.g., client, users, developers, admins).
• Define their roles and responsibilities.

C. Functional Requirements

• List the core functionalities in simple, clear terms.
• Example:
  • User Authentication (Sign up, Login, Forgot Password)
  • Product Management (Add, Edit, Delete, View)
  • Payment Processing (bKash, Stripe, PayPal)

D. Non-Functional Requirements

• Performance: Expected response time, concurrency handling.
• Security: Authentication, Authorization, Data encryption.
• Scalability: Should the system handle increasing users/data?
• Availability: Should it be accessible 24/7?

E. User Roles & Permissions

Role	Permissions
SuperAdmin	Full access to all features
Admin	Manage users, products, orders
User/Student	Can place orders, view products

F. API Endpoints (If Backend is Involved)

Method	Endpoint	Description
POST	/api/auth/register	Register new user
POST	/api/auth/login	User login
GET	/api/products	Get all products
POST	/api/order	Place a new order

G. Tech Stack Decision

• Frontend: React.js, Next.js, Vue.js
• Backend: Node.js, Express.js, Django
• Database: MongoDB, PostgreSQL, MySQL
• Hosting: Vercel, AWS, DigitalOcean

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2. Database Design

A. Identify Entities

Entities are the main objects in the system. Examples:

• Users
• Products
• Orders
• Payments

B. Define Relationships

• One-to-Many: A user can have multiple orders.
• Many-to-Many: Products can belong to multiple categories.

C. Create Database Schema

For MongoDB (Mongoose Schema Example):

const mongoose = require('mongoose');

const UserSchema = new mongoose.Schema({
  name: String,
  email: { type: String, unique: true },
  password: String,
  role: { type: String, enum: ['student', 'admin', 'superAdmin'], default: 'student' }
}, { timestamps: true });

const ProductSchema = new mongoose.Schema({
  name: String,
  description: String,
  price: Number,
  stock: Number,
  category: String
}, { timestamps: true });

const OrderSchema = new mongoose.Schema({
  userId: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },
  products: [{ productId: mongoose.Schema.Types.ObjectId, quantity: Number }],
  totalPrice: Number,
  status: { type: String, enum: ['pending', 'shipped', 'delivered'], default: 'pending' }
}, { timestamps: true });

module.exports = {
  User: mongoose.model('User', UserSchema),
  Product: mongoose.model('Product', ProductSchema),
  Order: mongoose.model('Order', OrderSchema)
};

For SQL (PostgreSQL Example):

CREATE TABLE users (
    id SERIAL PRIMARY KEY,
    name VARCHAR(100),
    email VARCHAR(100) UNIQUE,
    password TEXT,
    role VARCHAR(20) CHECK (role IN ('student', 'admin', 'superAdmin'))
);

CREATE TABLE products (
    id SERIAL PRIMARY KEY,
    name VARCHAR(100),
    description TEXT,
    price DECIMAL(10,2),
    stock INT,
    category VARCHAR(50)
);

CREATE TABLE orders (
    id SERIAL PRIMARY KEY,
    user_id INT REFERENCES users(id),
    total_price DECIMAL(10,2),
    status VARCHAR(20) CHECK (status IN ('pending', 'shipped', 'delivered'))
);

CREATE TABLE order_items (
    id SERIAL PRIMARY KEY,
    order_id INT REFERENCES orders(id),
    product_id INT REFERENCES products(id),
    quantity INT
);

D. Consider Indexing & Optimization

• Index fields like email and productId for faster queries.
• Use caching (Redis) for frequently accessed data.
• Implement pagination for large datasets.

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Final Steps

1. Create ERD (Entity Relationship Diagram) – Visual representation of tables/collections.
2. Define API Contracts – Use Swagger/Postman to document endpoints.
3. Review & Validate – Ensure the design aligns with project requirements.
4. Set Up Dev Environment – Initialize database, seed sample data.