create database biblioteca;
use biblioteca;
create table libros(
  codigo int,
  nombre varchar(100),
  genero varchar(100)
);
insert into libros values(1,'Harry Poter','aventura');
insert into libros values(2,'IT','terror');
insert into libros values(3,'LOTR','aventura');



package paquete;

public class Principal {
    public static void main(String[] args) {
        VentanaLibro v = new VentanaLibro();
        v.setVisible(true);

    }
}


package paquete;

import java.sql.*;
import javax.swing.table.*;

public class VentanaLibro extends javax.swing.JFrame {
    public void cargarGrilla(){
        try{
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(
            "jdbc:mysql://localhost/biblioteca","root","1234");
            Statement comando = con.createStatement();
            ResultSet resultado = comando.executeQuery(
                    "select * from libros");
            DefaultTableModel datos =
                    (DefaultTableModel) jTable1.getModel();
            datos.setRowCount(0);
            while(resultado.next()){
                String[] fila = {
                    resultado.getString("codigo"),
                    resultado.getString("nombre"),
                    resultado.getString("genero")
                };
                datos.addRow(fila);
            }

        } catch(Exception e){
            System.out.println(e);
        }
    }
    public VentanaLibro() {
        initComponents();
        cargarGrilla();
    }
    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        try{
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(
            "jdbc:mysql://localhost/biblioteca","root","1234");
            Statement comando = con.createStatement();
            String sql = "insert into libros values('%1','%2','%3')";
            sql = sql.replace("%1",jTextField1.getText());
            sql = sql.replace("%2",jTextField2.getText());
            sql = sql.replace("%3",jTextField3.getText());
            comando.execute(sql);
            System.out.println(sql);
            cargarGrilla();
        } catch(Exception e){
            System.out.println(e);
        }
    }

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
                try{
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(
            "jdbc:mysql://localhost/biblioteca","root","1234");
            Statement comando = con.createStatement();
            String sql = "delete from libros where codigo = "
                    + jTextField1.getText();
            comando.execute(sql);
            System.out.println(sql);
            cargarGrilla();
        } catch(Exception e){
            System.out.println(e);
        }
    }

    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
        try{
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(
            "jdbc:mysql://localhost/biblioteca","root","1234");
            Statement comando = con.createStatement();
            String sql =
            "update libros set nombre='%2',genero='%3' where codigo='%1' ";
            sql = sql.replace("%1",jTextField1.getText());
            sql = sql.replace("%2",jTextField2.getText());
            sql = sql.replace("%3",jTextField3.getText());
            comando.execute(sql);
            System.out.println(sql);
            cargarGrilla();
        } catch(Exception e){
            System.out.println(e);
        }
    }
   // Variables declaration - do not modify
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable jTable1;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField jTextField2;
    private javax.swing.JTextField jTextField3;
    // End of variables declaration
}