Transaction Tracker API

A REST API built with Go and Gin framework for managing financial transactions with full CRUD operations and MySQL database integration.

Features

• Full CRUD Operations: Create, Read, Update, and Delete transactions
• Filter by Type: Get transactions by income/expense type
• Input Validation: Data validation with proper error handling
• Modular Architecture: Clean separation with controllers, models, routes
• JSON API: RESTful endpoints with JSON responses

Tech Stack

• Language: Go 1.24.1
• Framework: Gin v1.10.0
• Database: MySQL
• Driver: go-sql-driver/mysql v1.9.2

Project Structure

transaction-tracker/
├── controllers/           # HTTP handlers
├── database/             # DB connection
├── models/               # Data structures
├── routes/               # Route definitions
├── create-tables.sql     # Database schema
├── main.go              # Entry point
└── README.md

Quick Start

1. Clone and install:

git clone https://github.com/MalshaPG/transaction-tracker.git
cd transaction-tracker
go mod tidy

2. Set environment variables:

# Linux/Mac
export DBUSER=username
export DBPASS=password

# Windows
set DBUSER=username
set DBPASS=password

3. Setup database: Run the SQL from create-tables.sql to create the database and sample data.

4. Run the application:

go run main.go

Server starts on localhost:8080

API Endpoints

Method	Endpoint	Description
GET	/transactions	Get all transactions
GET	/transactions/:type	Get transactions by type
POST	/transactions	Create a new transaction
PUT	/transactions/:id	Update a transaction
DELETE	/transactions/:id	Delete a transaction

Usage Examples

Get all transactions:

curl http://localhost:8080/transactions

Create transaction:

curl -X POST http://localhost:8080/transactions \
  -H "Content-Type: application/json" \
  -d '{
    "type": "income",
    "description": "Salary",
    "date": "2025-01-20",
    "amount": 5000.00
  }'

Update transaction:

curl -X PUT http://localhost:8080/transactions/1 \
  -H "Content-Type: application/json" \
  -d '{
    "type": "expense",
    "description": "Updated expense",
    "date": "2025-01-20",
    "amount": 100.00
  }'

Delete transaction:

curl -X DELETE http://localhost:8080/transactions/1

Transaction Object

{
  "id": 1,
  "type": "income",           // "income" or "expense"
  "description": "Salary",    // required, max 200 chars
  "date": "2025-01-01",      // YYYY-MM-DD format
  "amount": 5000.00          // must be > 0
}

Validation Rules

• Type: Must be "income" or "expense" (case-insensitive)
• Description: Required, non-empty, max 200 characters
• Date: Required, YYYY-MM-DD format
• Amount: Required, must be greater than 0

Database Schema

CREATE TABLE transactions (
    id INT AUTO_INCREMENT NOT NULL,
    type VARCHAR(100) NOT NULL,
    description VARCHAR(200) NOT NULL,
    date DATE NOT NULL,
    amount DECIMAL(20, 2) NOT NULL,
    CONSTRAINT pk_transactions PRIMARY KEY (id)   
);

HTTP Status Codes

• 200 OK - Successful GET/PUT
• 201 Created - Successful POST
• 204 No Content - Successful DELETE
• 400 Bad Request - Invalid input
• 404 Not Found - Resource not found
• 500 Internal Server Error - Server/DB error

License

This is a personal project made available for educational purposes. Feel free to fork and use as you like.