Operaciones CRUD

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;

public class CRUDSQLite {
    public static void main(String[] args) {
        String url = "jdbc:sqlite:persons.db";

        // Crear la tabla de persona si no existe
        try (Connection conn = DriverManager.getConnection(url);
             PreparedStatement stmt = conn.prepareStatement(
                     "CREATE TABLE IF NOT EXISTS person (cod INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INT)"
             )) {
            stmt.execute();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        }

        int opcion;
        Scanner scanner = new Scanner(System.in);

        do {
            System.out.println("\nMenú:");
            System.out.println("1. Añadir");
            System.out.println("2. Ver");
            System.out.println("3. Editar");
            System.out.println("4. Eliminar");
            System.out.println("5. Salir");
            System.out.print("Elija una opción: ");
            opcion = scanner.nextInt();

            switch (opcion) {
                case 1:
                    añadirPersona(url);
                    break;
                case 2:
                    verPersonas(url);
                    break;
                case 3:
                    editarPersona(url);
                    break;
                case 4:
                    eliminarPersona(url);
                    break;
            }
        } while (opcion != 5);
    }

    public static void añadirPersona(String url) {
        try (Connection conn = DriverManager.getConnection(url)) {
            conn.setAutoCommit(false);

            Scanner scanner = new Scanner(System.in);
            System.out.print("Nombre: ");
            String name = scanner.nextLine();
            System.out.print("Edad: ");
            int age = scanner.nextInt();

            try (PreparedStatement stmt = conn.prepareStatement("INSERT INTO person (name, age) VALUES (?, ?)")) {
                stmt.setString(1, name);
                stmt.setInt(2, age);
                stmt.executeUpdate();
                conn.commit();
                System.out.println("Persona añadida con éxito.");
            } catch (SQLException e) {
                conn.rollback();
                System.out.println("Error al añadir persona: " + e.getMessage());
            }
        } catch (SQLException e) {
            System.out.println("Error al conectar a la base de datos: " + e.getMessage());
        }
    }

    public static void verPersonas(String url) {
        try (Connection conn = DriverManager.getConnection(url);
             PreparedStatement stmt = conn.prepareStatement("SELECT cod, name, age FROM person");
             ResultSet rs = stmt.executeQuery()) {
            System.out.println("\nPersonas en la base de datos:");
            while (rs.next()) {
                System.out.println("Código: " + rs.getInt("cod"));
                System.out.println("Nombre: " + rs.getString("name"));
                System.out.println("Edad: " + rs.getInt("age"));
                System.out.println();
            }
        } catch (SQLException e) {
            System.out.println("Error al ver personas: " + e.getMessage());
        }
    }

    public static void editarPersona(String url) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Código de la persona a editar: ");
        int cod = scanner.nextInt();

        if (existePersona(url, cod)) {
            System.out.print("Nuevo nombre: ");
            String nuevoNombre = scanner.next();
            System.out.print("Nueva edad: ");
            int nuevaEdad = scanner.nextInt();

            try (Connection conn = DriverManager.getConnection(url)) {
                conn.setAutoCommit(false);

                try (PreparedStatement stmt = conn.prepareStatement("UPDATE person SET name = ?, age = ? WHERE cod = ?")) {
                    stmt.setString(1, nuevoNombre);
                    stmt.setInt(2, nuevaEdad);
                    stmt.setInt(3, cod);
                    stmt.executeUpdate();
                    conn.commit();
                    System.out.println("Persona editada con éxito.");
                } catch (SQLException e) {
                    conn.rollback();
                    System.out.println("Error al editar persona: " + e.getMessage());
                }
            } catch (SQLException e) {
                System.out.println("Error al conectar a la base de datos: " + e.getMessage());
            }
        } else {
            System.out.println("Persona no encontrada.");
        }
    }

    public static void eliminarPersona(String url) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Código de la persona a eliminar: ");
        int cod = scanner.nextInt();

        if (existePersona(url, cod)) {
            try (Connection conn = DriverManager.getConnection(url)) {
                conn.setAutoCommit(false);

                try (PreparedStatement stmt = conn.prepareStatement("DELETE FROM person WHERE cod = ?")) {
                    stmt.setInt(1, cod);
                    stmt.executeUpdate();
                    conn.commit();
                    System.out.println("Persona eliminada con éxito.");
                } catch (SQLException e) {
                    conn.rollback();
                    System.out.println("Error al eliminar persona: " + e.getMessage());
                }
            } catch (SQLException e) {
                System.out.println("Error al conectar a la base de datos: " + e.getMessage());
            }
        } else {
            System.out.println("Persona no encontrada.");
        }
    }

    public static boolean existePersona(String url, int cod) {
        try (Connection conn = DriverManager.getConnection(url);
             PreparedStatement stmt = conn.prepareStatement("SELECT 1 FROM person WHERE cod = ?")) {
            stmt.setInt(1, cod);
            try (ResultSet rs = stmt.executeQuery()) {
                return rs.next();
            }
        } catch (SQLException e) {
            System.out.println("Error al verificar existencia de persona: " + e.getMessage());
        }
        return false;
    }
}