jdbc program

package Unit4;  
  
import java.sql.*;  
import java.util.Scanner;  
  
public class JDBCQ1 {  
    public static void main(String[] args) {  
  
        // set all the fields        String dbUrl = "jdbc:mysql://localhost:3306/college";  
        String dbUser = "root";  
        String dbPass = "";  
  
        try {  
  
            // step 2 checvk for ther driver            Class.forName("com.mysql.cj.jdbc.Driver");  
            System.out.println("driver loaded");  
  
            // step 3 establish connection  
            Connection con = DriverManager.getConnection(dbUrl, dbUser, dbPass);  
            System.out.println("connected to db!");  
  
            add(con);  
            update(con);  
            view(con);  
            remove(con);  
  
        } catch (Exception e) {  
            System.out.println(e.getMessage());  
        }  
  
    }  
    public static void add(Connection con){  
        try {  
            // design preparedStatement            String query = "INSERT INTO students (name, rollno, age, email) VALUES (?,?,?,?)";  
            PreparedStatement psmt = con.prepareStatement(query);  
  
            // take input            Scanner sc = new Scanner(System.in);  
  
            System.out.println("name:");  
            String name = sc.nextLine();  
  
            System.out.println("Enter rollno:");  
            int rollno = Integer.valueOf(sc.nextLine());  
  
            System.out.println("age:");  
            int age = Integer.valueOf(sc.nextLine());  
  
            System.out.println("Enter email:");  
            String email = sc.nextLine();  
  
            psmt.setString(1, name);  
            psmt.setInt(2, rollno);  
            psmt.setInt(3, age);  
            psmt.setString(4, email);  
  
  
  
  
        } catch (SQLException e) {  
            throw new RuntimeException(e);  
        }    }  
    public static void update(Connection con) {  
        try {  
            Scanner sc = new Scanner(System.in);  
            System.out.println("Enter rollno of student to update:");  
            int rollno = Integer.parseInt(sc.nextLine());  
  
            System.out.println("New name:");  
            String name = sc.nextLine();  
  
            System.out.println("New age:");  
            int age = Integer.parseInt(sc.nextLine());  
  
            System.out.println("New email:");  
            String email = sc.nextLine();  
  
            String query = "UPDATE students SET name = ?, age = ?, email = ? WHERE rollno = ?";  
            PreparedStatement psmt = con.prepareStatement(query);  
            psmt.setString(1, name);  
            psmt.setInt(2, age);  
            psmt.setString(3, email);  
            psmt.setInt(4, rollno);  
  
            int rows = psmt.executeUpdate();  
            System.out.println(rows + " record(s) updated.");  
  
        } catch (SQLException e) {  
            throw new RuntimeException(e);  
        }    }  
    public static void remove(Connection con) {  
        try {  
            Scanner sc = new Scanner(System.in);  
            System.out.println("Enter rollno of student to delete:");  
            int rollno = Integer.parseInt(sc.nextLine());  
  
            String query = "DELETE FROM students WHERE rollno = ?";  
            PreparedStatement psmt = con.prepareStatement(query);  
            psmt.setInt(1, rollno);  
  
            int rows = psmt.executeUpdate();  
            System.out.println(rows + " record(s) deleted.");  
  
        } catch (SQLException e) {  
            throw new RuntimeException(e);  
        }    }  
    public static void view(Connection con) {  
        try {  
            String query = "SELECT * FROM students";  
            PreparedStatement psmt = con.prepareStatement(query);  
            ResultSet rs = psmt.executeQuery();  
  
            System.out.println("RollNo\tName\tAge\tEmail");  
            System.out.println("----------------------------------------");  
  
            while (rs.next()) {  
                int rollno = rs.getInt("rollno");  
                String name = rs.getString("name");  
                int age = rs.getInt("age");  
                String email = rs.getString("email");  
  
                System.out.println(rollno + "\t" + name + "\t" + age + "\t" + email);  
            }  
        } catch (SQLException e) {  
            throw new RuntimeException(e);  
        }    }  
  
  
  
  
}