Employee Database Management System

This is a simple Java application that interacts with a relational database to manage employee data. It uses JDBC to perform CRUD (Create, Read, Update, Delete) operations on an employee table in the employee_db database. The application consists of an Employee entity class and an EmployeeData class for handling database operations.

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Features

• Create: Add new employees to the database.
• Read: Fetch details of a specific employee or list all employees.
• Update: Modify details of an existing employee.
• Delete: Remove an employee from the database.

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Requirements

• Java Development Kit (JDK): 8 or higher.
• Apache Maven: For dependency management.
• PostgreSQL Database: As the relational database system.
• PostgreSQL JDBC Driver: Added as a Maven dependency.

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Database Setup

1. Install and start PostgreSQL Server.
2. Open a PostgreSQL client (e.g., pgAdmin or terminal).
3. Create the employee_db database:

   CREATE DATABASE employee_db;

4. Connect to the employee_db database:

   \c employee_db

5. Create the employee table:

   CREATE TABLE employee (
       id SERIAL PRIMARY KEY,
       name VARCHAR(100) NOT NULL,
       position VARCHAR(100) NOT NULL,
       salary DOUBLE PRECISION NOT NULL,
       hire_date DATE NOT NULL
   );

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How to Run the Program

Step 1: Clone the Repository

Clone the project repository from GitHub:

git clone https://github.com/your-username/employee-management-system.git
cd employee-management-system

Step 2: Build the Project

Use Maven to build the project:

mvn clean install

Step 3: Configure Database Connection

Update the database connection details in the EmployeeData class:

private static final String URL = "jdbc:postgresql://localhost:5432/employee_db";
private static final String USER = "postgres"; // Replace with your PostgreSQL username
private static final String PASSWORD = "yourpassword"; // Replace with your PostgreSQL password

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Sample Operations

Create an Employee

The application will insert a new employee into the employee table.

Database State:

INSERT INTO employee (name, position, salary, hire_date)
VALUES ('Student AlaToo', 'HR Manager', 60000, '2023-01-15');

SELECT * FROM employee WHERE id = 1;

UPDATE employee
SET salary = 65000
WHERE id = 1;

DELETE FROM employee WHERE id = 1;

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Project Structure

employee-database-management-system
├── src
│   ├── main
│   │   ├── java
│   │   │   └── com.example
│   │   │       ├── App.java          # Main application
│   │   │       ├── Employee.java     # Employee entity class
│   │   │       └── EmployeeData.java # Database operations class
│   └── test
│       └── java
│           └── com.example
│               └── AppTest.java      # Unit tests (optional)
└── pom.xml                           # Maven configuration