💾 Java SQL Practice - Customer & Order Management

📂 Project Description

This is a console-based Java application that demonstrates working with a MySQL database using JDBC. The project showcases CRUD operations, SQL queries, and table joins (JOIN) in practice.

🔹 The application allows you to:

• Add, view, update, and delete users (users) and orders (orders);
• Join tables to display orders along with their associated users;
• Automatically format user input (capitalize first letters of names);
• Automatically assign the current date to new orders;
• Validate user input for correctness.

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🔧 Technologies

• Java 17+
• JDBC
• MySQL
• Maven (for dependency management, e.g., mysql-connector-java)
• Console interface

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📌 Database Setup

Create Database

CREATE DATABASE IF NOT EXISTS java_practice;
USE java_practice;

Users Table (users)

CREATE TABLE users(
    UserID INT PRIMARY KEY AUTO_INCREMENT,
    LastName VARCHAR(50),
    FirstName VARCHAR(50),
    DateOfBirth DATE
);

Orders Table (orders)

CREATE TABLE orders(
    OrderID INT PRIMARY KEY AUTO_INCREMENT,
    UserID INT,
    Product VARCHAR(50),
    Total_Price DECIMAL(10,2),
    Order_Date DATE DEFAULT CURRENT_DATE,
    FOREIGN KEY (UserID) REFERENCES users(UserID)
);

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🚗 How to Run

1. Add MySQL connector dependency in Maven:

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.1.0</version>
</dependency>

2. Set up your database connection in DatabaseConnection class.
3. Run Main.java to start the application.

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☝️ Features

• Automatic capitalization of first letters in names (Capitalize.capitalizeFirstLetter());
• Secure SQL queries using PreparedStatement;
• Input validation for ID, price, and date;
• Display orders with user information and order date;
• Support for deleting individual entries and cleaning entire tables.

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👨‍💻 Author

Oleksii (GitHub)