src/main/java/database/dao/StudentDaoImpl.java - master - Zakonreal/practice06

src/main/java/database/dao/StudentDaoImpl.java
110 строк4 KB
RodinRoman
init
15 май 2025, 03:23
15 май 2025, 03:2317d6e58
package database.dao;

import database.model.Student;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class StudentDaoImpl implements StudentDao {

    public Connection connection;

    public StudentDaoImpl(Connection connection) {
        this.connection = connection;
    }

    @Override
    public List<Student> getAll() {
        List<Student> students = new ArrayList<>();
        String sql = "select * from students";

        try (Statement statement = connection.createStatement();
             ResultSet resultSet = statement.executeQuery(sql)
        ){
            while (resultSet.next()) {
                Student student = new Student();
                student.setId(resultSet.getInt("id"));
                student.setName(resultSet.getString("name"));
                student.setMark(resultSet.getInt("mark"));

                students.add(student);
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        return students;
    }

    @Override
    public Student getById(int id) {
        Student student = null;
        String sql = "select * from students where id = ?";
        try (PreparedStatement statement = connection.prepareStatement(sql)){
            statement.setInt(1, id);
            try (ResultSet resultSet = statement.executeQuery()){
                if (resultSet.next()) {
                    student = new Student();
                    student.setId(resultSet.getInt("id"));
                    student.setName(resultSet.getString("name"));
                    student.setMark(resultSet.getInt("mark"));
                }
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        return student;
    }

    @Override
    public void add(Student student) {
        String sql = "insert into students(id, name, mark) values(?, ?, ?)";
        try (PreparedStatement statement = connection.prepareStatement(sql)){
            statement.setInt(1, student.getId());
            statement.setString(2, student.getName());
            statement.setInt(3, student.getMark());

            statement.executeUpdate();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void update(Student student) {
        String sql = "update students set name = ?, mark = ? where id = ?";
        try (PreparedStatement statement = connection.prepareStatement(sql)){
            statement.setString(1, student.getName());
            statement.setInt(2, student.getMark());
            statement.setInt(3, student.getId());

            statement.executeUpdate();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void deleteById(int id) {
        String sql = "delete from students where id = ?";
        try (PreparedStatement statement = connection.prepareStatement(sql)){
            statement.setInt(1, id);

            statement.executeUpdate();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void init() {
        System.out.println("database initializing...");
        String sql = "create table students " +
                "(id integer not null, name varchar(255) not null, mark integer not null, primary key(id))";
        try (Statement statement = connection.createStatement()) {
            statement.executeUpdate(sql);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}