connect database

package nguyenvanquan7826.test;

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

public class MyConnection {
    private Connection connection;
    private final String driver = "com.mysql.jdbc.Driver";
    private final String dataName = "jdbc:mysql://localhost:3306/student";
    private final String user = "root";
    private final String pass = "lamgicopass";

    public static void main(String[] args) {
        // create connect
        MyConnection connect = new MyConnection();
        // connect database
        connect.connect();

        while (true) {
            connect.showMenu();
        }
    }

    // show menu select method
    private void showMenu() {
        String tableName = "student_info";
        String id = "";
        Scanner scan = new Scanner(System.in);
        System.out.println("Select an method: ");
        System.out.println("1: show data in database");
        System.out.println("2: show student by id in database");
        System.out.println("3: delete student by id in database");
        System.out.println("4: update student info by id in database");
        System.out.println("5: insert student into database");
        System.out.println("6: exit");
        int select = Integer.parseInt(scan.nextLine());
        switch (select) {
        case 1:
            showData(getData(tableName));
            break;

        case 2:
            System.out.println("Enter id of student you want show:");
            id = scan.nextLine();
            showData(getDataId(tableName, id));
            break;
        case 3:
            System.out.println("Enter id of student you want delete:");
            id = scan.nextLine();
            deleteId(tableName, id);
            break;
        case 4:
            System.out.println("Enter id of student you want update:");
            id = scan.nextLine();
            updateId(tableName, id, createStudent());
            break;
        case 5:
            insertId(tableName, createStudent());
            break;
        case 6:
            System.exit(0);
        }
    }

    // connect to database
    private void connect() {
        try {
            Class.forName(driver);
            connection = DriverManager.getConnection(dataName, user, pass);
            System.out.println("Ket noi thanh cong");
            System.out.println("~~~~~~~~~~~~~~~~~~");
        } catch (ClassNotFoundException e) {
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    // disconnect to database
    private void disconnect() {
        try {
            connection.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    // show data in resultset - data is selected
    private void showData(ResultSet rs) {
        System.out.printf("%-5s %-20s %-5s\n", "Id", "Name", "Point");
        System.out.printf("--------------------------------\n");
        try {
            while (rs.next()) {
                System.out.printf("%-5s %-20s %-5.2f\n", rs.getString(1),
                        rs.getString(2), rs.getDouble(3));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println("~~~~~~~~~~~~~~~~~~");
    }

    // get data from database
    private ResultSet getData(String tableName) {
        ResultSet rs = null;
        String sqlCommand = "select * from " + tableName;
        try {
            Statement statement = connection.createStatement();
            rs = statement.executeQuery(sqlCommand);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rs;
    }

    // get Student by id
    private ResultSet getDataId(String tableName, String id) {
        ResultSet rs = null;
        String sqlCommand = "select * from " + tableName + " where `id` = ?";
        PreparedStatement ps;
        try {
            ps = connection.prepareStatement(sqlCommand);
            ps.setString(1, id);
            rs = ps.executeQuery();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rs;
    }

    // delete student by id
    private void deleteId(String tableName, String id) {
        String sqlCommand = "delete from " + tableName + " where `id` = ?";
        PreparedStatement ps;
        try {
            ps = connection.prepareStatement(sqlCommand);
            ps.setString(1, id);
            if (ps.executeUpdate() > 0) {
                System.out.println("delete success!");
            } else {
                System.out.println("error delete");
            }
        } catch (SQLException e) {
            System.out.println("error delete");
        }
    }

    // update student by id
    private void updateId(String tableName, String id, Student student) {
        String sqlCommand = "update " + tableName
                + " set `name` = ?, `point` = ? where `id` = ?";
        PreparedStatement ps;
        try {
            ps = connection.prepareStatement(sqlCommand);
            ps.setString(1, student.getName());
            ps.setDouble(2, student.getPoint());
            ps.setString(3, student.getId());
            if (ps.executeUpdate() > 0) {
                System.out.println("update success!");
            } else {
                System.out.println("error update 1 ");
            }
        } catch (SQLException e) {
            System.out.println("error update 2" + e.toString());
        }
    }

    // insert a student
    private void insertId(String tableName, Student student) {
        String sqlCommand = "insert into " + tableName + " value(?, ?, ?)";
        PreparedStatement ps;
        try {
            ps = connection.prepareStatement(sqlCommand);
            ps.setString(1, student.getId());
            ps.setString(2, student.getName());
            ps.setDouble(3, student.getPoint());
            if (ps.executeUpdate() > 0) {
                System.out.println("insert success!");
            } else {
                System.out.println("error insert");
            }
        } catch (SQLException e) {
            System.out.println("error insert");
        }
    }

    // create a student
    private Student createStudent() {
        Scanner scan = new Scanner(System.in);
        Student student = null;
        System.out.println("Enter id, name and point of student");
        String id = scan.nextLine();
        String name = scan.nextLine();
        double point = Double.parseDouble(scan.nextLine());
        student = new Student(id, name, point);
        return student;
    }

}

class Student {
    private String id;
    private String name;
    private double point;

    public Student(String id, String name, double point) {
        super();
        this.id = id;
        this.name = name;
        this.point = point;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getPoint() {
        return point;
    }

    public void setPoint(double point) {
        this.point = point;
    }

}