StuTest.java

import java.util.Scanner;
import java.sql.*;
public class StuTest { }

// Kindly concentrate on sql commands

 class JDBCcalls {
   public  Connection con=null;
   public PreparedStatement ps = null;
    JDBCcalls() throws SQLException {
      // kindly change the url as per your system
      con = DriverManager.getConnection("jdbc:mysql://localhost:3308/Studatabase", "root", "");
    }

    public  void insert(String a,String b,String c,String d,String e) throws SQLException {
      int a1 = Integer.parseInt(a);
      int e1 = Integer.parseInt(e);
      String str = "insert into stu values(" + a1 + ",'" + b + "','" + c + "','" + d + "'," + e1 + ")";
      System.out.println(str);

      ps = con.prepareStatement(str);
      ps.executeUpdate();
    }

    public void delete(String a) throws SQLException
    {
      Integer a1=Integer.parseInt(a);
      String str1 = "delete from stu where rollno="+a;
      System.out.println(str1);
      ps=con.prepareStatement(str1);
      ps.executeUpdate();
    }
    public void modify(String a, String e) throws SQLException
    {
      int a1= Integer.parseInt(a);
      int e1=Integer.parseInt(e);
      String str2 = "update stu set fee="+e1+" where rollno ="+ a1;
      System.out.println(str2);
      PreparedStatement ps=con.prepareStatement(str2);
      ps.executeUpdate();
    }

    public void display(String a) throws SQLException {
      Integer a1 = Integer.parseInt(a);
      Statement s = con.createStatement();
      ResultSet rs = s.executeQuery("SELECT * FROM stu where rollno =" + a1);
      while (rs.next()) {
        System.out.println(rs.getInt(1));
        System.out.println(rs.getString(2));
        System.out.println(rs.getString(3));
        System.out.println(rs.getString(4));
        System.out.println(rs.getInt(5));

      }
    }
  public static void main(String[] args) throws ClassNotFoundException, SQLException
  {
    Class.forName("com.mysql.cj.jdbc.Driver");
    Scanner sc = new Scanner(System.in);
    //DAO d=new DAO();
    System.out.println("--------------------------------------------------------------------------------------------------------------------");
    System.out.println("Press 1. Inserting the record and all other details are the values for the columns in each row of the student table");
    System.out.println("Press 2. Deleting a record and 101 is the roll no of the student, whose record has to be deleted.");
    System.out.println("Press 3. Modifying a record and the 4500 is the new fee which needs to replace the old fee value");
    System.out.println("Press 4. Displaying the record");
    System.out.println("Press 0. For exit the program");
    System.out.println("--------------------------------------------------------------------------------------------------------------------");
    JDBCcalls d = new JDBCcalls();

    // Switch with -> not supported in java 12
    // so i changed it inot normal representation
    switch (args[0])
    {
      case "0":
        break;
      case "1":
        d.insert(args[1],args[2],args[3],args[4],args[5]);
        System.out.println("record Inserted");
      break;
      case "2":
        d.delete(args[1]);
        System.out.println("record Deleted");
      break;
      case "3":
          d.modify(args[1],args[2]);
      break;
      case "4":
        d.display(args[1]);
      break;
      default:
        System.out.println("enter choice again");
    }
  }
}