Zero Exception – Java, Spring Boot & System Design Tutorials

Write a Java program to accept the details of patient(pno, pname) from user and insert it into the database, display it and delete the record of entered pno from the table

Program:

import java.io.*;
import java.sql.*;
import java.awt.*;
import java.awt.event.*;

public class Patient extends Frame implements ActionListener {
    Label labelPNo, labelPName;
    TextField textPNo, textPName;
    Button btnAdd, btnDelete;
    String sql;
    Statement stmt;
    Connection con;

    public Patient() throws SQLException, ClassNotFoundException {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        con = DriverManager.getConnection("jdbc:odbc:patientDSN");
        setLayout(new FlowLayout());
        setSize(300,200);

        labelPNo = new Label("Patient No:");
        labelPName = new Label("Patient Name:");
        textPNo = new TextField(20);
        textPName = new TextField(20);
        btnAdd = new Button("Add");
        btnDelete = new Button("Delete");

        btnAdd.addActionListener(this);
        btnDelete.addActionListener(this);

        add(labelPNo);
        add(textPNo);
        add(labelPName);
        add(textPName);
        add(btnAdd);
        add(btnDelete);
        addWindowListener(new WClose());
        setVisible(true);
    }

    public void actionPerformed(ActionEvent ae) {
        try {
            if(ae.getSource == btnAdd){
                int pno;
                String pname;
                pno = Integer.parseInt(textPNo.getText());
                pname = textPName.getText();
                sql = "insert into patient values("+pno+",'"+pname+"')";
                stmt = con.createStatement();
                int k = s.executeUpdate(sql);
                if(k>0) {
                    System.out,println("Record Saved.");
                }
                stmt.close();
            }

            if(ae.getSource() == btnDelete){
                int pno;
                pno = Integer.parseInt(textPNo.getText());
                sql = "delete from patient where pno="+pno;
                stmt = con.createStatement();
                int k = s.executeUpdate(sql);
                if(k>0) {
                    System.out,println("Record Deleted.");
                }
                stmt.close();
            }
            
        } catch (Exception e) {
            System.out.println(e);
        }
    }
    public static void main(String args[]){
        new Patient();
    }
}

class WClose extends WindowAdapter {
    public void windowClosing(WindowEvent we) {
        System.exit(0);
    }
}