💰 Smart Expense Tracker (C++ Edition)

A production-ready command-line expense tracker built in C++17 with a SQLite backend. Track daily spending, organize expenses by category, and get automatic insights — category breakdowns, monthly reports, and smart budget warnings.

✨ Perfect for learning: OOP design patterns, database management, and CLI applications in modern C++!

This is a C++ rewrite of an earlier Python/Pandas version, redesigned around object-oriented principles, raw SQL with prepared statements, and a custom in-memory analytics engine (no external data processing libraries).

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⚡ Key Features

• ✅ Full CRUD Operations — Add, view, update, and delete expense records with SQLite persistence
• 📊 Smart Filtering — Filter expenses by category or date range
• 📈 Advanced Analytics Engine — Category breakdowns, monthly reports, weekly (ISO week) reports, and summary insights
• 💡 Budget Alerts — Set monthly budgets per category and get notifications when you exceed them
• 🛡️ Data Validation — Strict validation for amounts, dates, and categories
• ⚙️ Optimized Database — Normalized schema with indexed queries for lightning-fast performance

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🏗️ Tech Stack

Layer	Technology
Language	C++17 (Modern C++)
Database	SQLite3 (via official C API)
Build System	Make + g++
Architecture	OOP with Clean Code Principles

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📂 Project Structure

Expense-Tracker/
├── include/
│   ├── Expense.h        # Data model for a single expense
│   ├── Database.h       # SQLite wrapper - schema, CRUD, queries
│   ├── Analytics.h      # Insights engine - breakdowns, reports
│   └── Tracker.h        # Application controller / CLI logic
├── src/
│   ├── Expense.cpp
│   ├── Database.cpp
│   ├── Analytics.cpp
│   ├── Tracker.cpp
│   └── main.cpp         # CLI entry point & menu system
├── Makefile
├── LICENSE              # MIT License
└── README.md

🎯 Architecture Overview

• Expense — Plain data class representing a single transaction (id, amount, category, description, date)
• Database — Manages SQLite connection, schema creation, and prepared-statement CRUD operations
• Analytics — Computes category totals, monthly/weekly aggregates, top spending, and budget comparisons
• Tracker — Controller class that validates input and orchestrates Database & Analytics operations

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🗄️ Database Schema

CREATE TABLE categories (
    name         TEXT PRIMARY KEY,
    budget_limit REAL DEFAULT 0
);

CREATE TABLE expenses (
    id          INTEGER PRIMARY KEY AUTOINCREMENT,
    amount      REAL NOT NULL,
    category    TEXT NOT NULL,
    description TEXT,
    date        TEXT NOT NULL,
    FOREIGN KEY (category) REFERENCES categories(name)
);

CREATE INDEX idx_expenses_category ON expenses(category);
CREATE INDEX idx_expenses_date     ON expenses(date);

Default Categories: Food, Transport, Utilities, Entertainment, Health, Shopping, Other

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🚀 Quick Start

Prerequisites

• C++17 compiler (g++ 9+ or equivalent)
• make build tool
• SQLite3 development headers

Ubuntu/Debian:

sudo apt update
sudo apt install build-essential libsqlite3-dev

macOS (Homebrew):

brew install sqlite3

Build & Run

# Clone the repository
git clone https://github.com/yashkumar3006/Expense-Tracker.git
cd Expense-Tracker

# Build the project
make

# Run the application
./expense_tracker
# or simply: make run

A SQLite database (expenses.db) is created automatically on first run.

Clean Build Artifacts

make clean

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💡 Usage Examples

Interactive Menu

================ SMART EXPENSE TRACKER ================
 1. Add Expense
 2. View All Expenses
 3. View Expenses by Category
 4. View Expenses by Date Range
 5. Update Expense
 6. Delete Expense
 --------------------------------------------------------
 7. Summary Report (full insights)
 8. Category Breakdown
 9. Monthly Report
10. Weekly Report
11. Budget Warnings
 --------------------------------------------------------
12. List Categories
13. Set Category Budget
 0. Exit
=========================================================

Adding an Expense

Select an option: 1
Enter amount: 450
Enter category: Food
Enter description: Lunch at a cafe
Enter date (YYYY-MM-DD): 2026-07-24
✓ Expense added successfully.

Sample Summary Report

========== EXPENSE SUMMARY REPORT ==========
Total Spend:    Rs. 3000.00
Total Records:  4
Top Category:   Food

--- Category Breakdown ---
  Entertainment  Rs.     800.00  (26.7%)
  Food           Rs.    2000.00  (66.7%)
  Transport      Rs.     200.00  (6.7%)

--- Monthly Report ---
  2026-06 : Rs. 3000.00

--- Weekly Report ---
  2026-W23 : Rs. 700.00
  2026-W24 : Rs. 2300.00

--- Budget Warnings ---
  Food: Spent Rs. 2000.00 / Budget Rs. 1500.00 ⚠️ OVER BUDGET!
==============================================

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🎓 Learning Outcomes

This project demonstrates:

• ✅ Modern C++17 features and best practices
• ✅ Object-Oriented Design principles
• ✅ SQL database integration and query optimization
• ✅ CLI application development
• ✅ Error handling and validation
• ✅ Memory management and resource cleanup

Perfect for students and developers looking to strengthen their C++ skills!

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🔮 Potential Enhancements

• 📄 Export reports to CSV/PDF
• 👥 Multi-user support with authentication
• 🔄 Recurring expense management
• 🎨 TUI interface using ncurses
• 📱 REST API wrapper
• 🔐 Data encryption support

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🤝 Contributing

Contributions are welcome! Here's how you can help:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/YourFeature)
3. Commit your changes (git commit -m 'Add awesome feature')
4. Push to the branch (git push origin feature/YourFeature)
5. Open a Pull Request

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📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

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🌟 Show Your Support

If you find this project helpful, please give it a ⭐ star on GitHub! It helps increase visibility and lets others discover it.

Have feedback or ideas? Feel free to open an Issue or start a Discussion.

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📞 Connect

• GitHub: @yashkumar3006
• Questions? Open an issue or discussion in the repository

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Made with ❤️ by Yash Kumar