🎯 Quiz App (Java 17 + MySQL + JDBC)

A console-based Online Quiz Application built with plain Java (17), MySQL, and JDBC.
This repo provides user registration/login (passwords hashed with BCrypt), admin functionality to create/manage quizzes, and user flows to attempt quizzes and store results.

Overview

This application demonstrates a simple, modular approach to building a quiz system using JDBC for database interactions. The code is organized as services (UserService, QuizService, AdminService) and a console UI (Main.java). All persistent data is stored in a MySQL database.

Features

• ✅ User registration and login (BCrypt hashed passwords)
• ✅ Role-based behavior: ADMIN and USER
• ✅ Admin can create quizzes and add questions
• ✅ Users can list quizzes and attempt them
• ✅ Results are stored in the database for later review

Prerequisites

• Java 17 (JDK 17) installed and JAVA_HOME configured
• Maven 3.6+
• MySQL 8+ running locally (or reachable remotely)
• Terminal or IDE (IntelliJ/Eclipse/VSCode)

Project structure

quiz-app/ │── src/main/java/com/quizapp/ │ ├── DBConnection.java # Database connection │ ├── UserService.java # Handles user login & registration │ ├── QuizService.java # Handles quiz logic │ ├── AdminService.java # Handles admin actions │ ├── Main.java # Entry point (menu-driven application) │ │── pom.xml # Maven dependencies & build

Database schema & sample data

Run these SQL commands in your MySQL client to create the database and tables used by the application.

#SQL

1. Create database CREATE DATABASE quizdb CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci; USE quizdb;

2. Users CREATE TABLE users ( id INT AUTO_INCREMENT PRIMARY KEY, username VARCHAR(255) UNIQUE NOT NULL, password VARCHAR(255) NOT NULL, -- BCrypt hash (~60 chars) role ENUM('ADMIN','USER') NOT NULL DEFAULT 'USER', created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP );

3. Quizzes CREATE TABLE quizzes ( id INT AUTO_INCREMENT PRIMARY KEY, title VARCHAR(255) NOT NULL, description TEXT, created_by INT, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP );

4. Questions (multiple choice stored in columns for simplicity) CREATE TABLE questions ( id INT AUTO_INCREMENT PRIMARY KEY, quiz_id INT NOT NULL, question_text TEXT NOT NULL, option_a VARCHAR(1024), option_b VARCHAR(1024), option_c VARCHAR(1024), option_d VARCHAR(1024), correct_option CHAR(1), -- 'A', 'B', 'C', 'D' FOREIGN KEY (quiz_id) REFERENCES quizzes(id) ON DELETE CASCADE );

5. Results (attempts) CREATE TABLE results ( id INT AUTO_INCREMENT PRIMARY KEY, user_id INT, quiz_id INT, score INT, total INT, correct INT, time_taken_seconds INT, taken_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP, FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL, FOREIGN KEY (quiz_id) REFERENCES quizzes(id) ON DELETE SET NULL );

🛠 Tech Stack

• Java 17
• MySQL 8+
• JDBC (Java Database Connectivity)
• Maven (dependency management & build tool)
• BCrypt for password hashing

⚙️ Installation & Setup

1️⃣ Clone the Repository

[git clone https://github.com/SidTirse-13/QUIZ_APP
cd quiz-app