Create a Java program to connect to a MySQL database and fetch data from a single table. The program should:

Use DriverManager and Connection objects.

Retrieve and display all records from a table named Employee with columns EmpID, Name, and Salary.

import java.sql.*; public class EmployeeData { public static void main(String[] args) { String url = "jdbc:mysql://localhost:3306/company"; String user = "root"; String password = "password"; // Replace with your password

    try {
        // Step 1: Load JDBC driver
        Class.forName("com.mysql.cj.jdbc.Driver");

        // Step 2: Establish connection
        Connection con = DriverManager.getConnection(url, user, password);
        System.out.println("Connected to the database!");

        // Step 3: Execute query
        Statement stmt = con.createStatement();
        ResultSet rs = stmt.executeQuery("SELECT * FROM Employee");

        // Step 4: Display result
        while (rs.next()) {
            System.out.println("EmpID: " + rs.getInt("EmpID") + ", Name: " + rs.getString("Name") +
                    ", Salary: " + rs.getDouble("Salary"));
        }

        // Step 5: Close connection
        con.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

}

Build a Java program to perform CRUD operations (Create, Read, Update, Delete) on a database table Product with columns:

ProductID, ProductName, Price, and Quantity.

The program should include:

Menu-driven options for each operation.

Transaction handling to ensure data integrity.

import java.sql.*; import java.util.Scanner;

public class ProductManager {

static Connection connection;

public static void connectDatabase() {
    try {
        Class.forName("com.mysql.cj.jdbc.Driver");
        connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/store", "root", "password");
        System.out.println("Database connected.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void createProduct() {
    try {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter Product ID: ");
        int id = scanner.nextInt();
        scanner.nextLine();
        System.out.print("Enter Product Name: ");
        String name = scanner.nextLine();
        System.out.print("Enter Price: ");
        double price = scanner.nextDouble();
        System.out.print("Enter Quantity: ");
        int quantity = scanner.nextInt();

        String query = "INSERT INTO Product (ProductID, ProductName, Price, Quantity) VALUES (?, ?, ?, ?)";
        PreparedStatement ps = connection.prepareStatement(query);
        ps.setInt(1, id);
        ps.setString(2, name);
        ps.setDouble(3, price);
        ps.setInt(4, quantity);
        ps.executeUpdate();
        System.out.println("Product added successfully.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void readProducts() {
    try {
        Statement stmt = connection.createStatement();
        ResultSet rs = stmt.executeQuery("SELECT * FROM Product");

        while (rs.next()) {
            System.out.println("ProductID: " + rs.getInt("ProductID") + ", ProductName: " + rs.getString("ProductName") +
                    ", Price: " + rs.getDouble("Price") + ", Quantity: " + rs.getInt("Quantity"));
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void updateProduct() {
    try {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter Product ID to update: ");
        int id = scanner.nextInt();
        System.out.print("Enter new Price: ");
        double price = scanner.nextDouble();

        String query = "UPDATE Product SET Price = ? WHERE ProductID = ?";
        PreparedStatement ps = connection.prepareStatement(query);
        ps.setDouble(1, price);
        ps.setInt(2, id);
        ps.executeUpdate();
        System.out.println("Product updated successfully.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void deleteProduct() {
    try {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter Product ID to delete: ");
        int id = scanner.nextInt();

        String query = "DELETE FROM Product WHERE ProductID = ?";
        PreparedStatement ps = connection.prepareStatement(query);
        ps.setInt(1, id);
        ps.executeUpdate();
        System.out.println("Product deleted successfully.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void main(String[] args) {
    connectDatabase();
    Scanner scanner = new Scanner(System.in);
    int choice;

    while (true) {
        System.out.println("1. Add Product\n2. View Products\n3. Update Product\n4. Delete Product\n5. Exit");
        System.out.print("Enter choice: ");
        choice = scanner.nextInt();

        switch (choice) {
            case 1 -> createProduct();
            case 2 -> readProducts();
            case 3 -> updateProduct();
            case 4 -> deleteProduct();
            case 5 -> {
                System.out.println("Exiting...");
                System.exit(0);
            }
            default -> System.out.println("Invalid choice. Please try again.");
        }
    }
}

}

Develop a Java application using JDBC and MVC architecture to manage student data. The application should:

Use a Student class as the model with fields like StudentID, Name, Department, and Marks.

Include a database table to store student data.

Allow the user to perform CRUD operations through a simple menu-driven view.

Implement database operations in a separate controller class.

import java.sql.; import java.util.;

public class StudentController { private Connection connection;

public StudentController() {
    try {
        Class.forName("com.mysql.cj.jdbc.Driver");
        connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/school", "root", "password");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

// Create Student
public void addStudent(Student student) {
    try {
        PreparedStatement ps = connection.prepareStatement("INSERT INTO students (StudentID, Name, Department, Marks) VALUES (?, ?, ?, ?)");
        ps.setInt(1, student.getStudentID());
        ps.setString(2, student.getName());
        ps.setString(3, student.getDepartment());
        ps.setInt(4, student.getMarks());
        ps.executeUpdate();
        System.out.println("Student added successfully.");
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

// Read Students
public void displayStudents() {
    try {
        Statement stmt = connection.createStatement();
        ResultSet rs = stmt.executeQuery("SELECT * FROM students");
        while (rs.next()) {
            System.out.println(rs.getInt("StudentID") + " | " + rs.getString("Name") + " | " +
                    rs.getString("Department") + " | " + rs.getInt("Marks"));
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

// Update Student
public void updateStudentMarks(int studentID, int marks) {
    try {
        PreparedStatement ps = connection.prepareStatement("UPDATE students SET Marks=? WHERE StudentID=?");
        ps.setInt(1, marks);
        ps.setInt(2, studentID);
        ps.executeUpdate();
        System.out.println("Student marks updated.");
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

// Delete Student
public void deleteStudent(int studentID) {
    try {
        PreparedStatement ps = connection.prepareStatement("DELETE FROM students WHERE StudentID=?");
        ps.setInt(1, studentID);
        ps.executeUpdate();
        System.out.println("Student deleted.");
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

}