hw5/src/main/java/courseSber/repositories/CoursesRepository.java - master - eelamimi/SberJavaCourseBeginner

hw5/src/main/java/courseSber/repositories/CoursesRepository.java
180 строк6 KB
glebka
fixed bugs
19 апр 2025, 15:26
19 апр 2025, 15:26f35dbdc
package courseSber.repositories;

import courseSber.enums.FieldsOfCourse;
import courseSber.models.Course;
import courseSber.utils.*;

import java.sql.*;
import java.util.*;

import static courseSber.utils.GetRS.getCourseFromResultSet;
import static courseSber.utils.SetPS.setCourseForPreparedStatement;

public class CoursesRepository {

    public List<Course> findAll() {
        String sql = "SELECT * FROM courses " +
                "INNER JOIN teachers ON courses.teacher_course = teachers.contract_teacher";
        List<Course> courses = new ArrayList<>();

        try (PreparedStatement ps = DBConnector.getConnection().prepareStatement(sql);
             ResultSet rs = ps.executeQuery()) {

            while (rs.next()) {
                Course course = getCourseFromResultSet(rs);
                courses.add(course);
            }
        } catch (SQLException e) {
            System.out.println("Ошибка при получении курсов: " + e.getMessage());
            e.printStackTrace();
            return null;
        }

        if (courses.isEmpty()) {
            return null;
        } else {
            return courses;
        }
    }

    public List<Course> findByField(String value, FieldsOfCourse field) {
        String sql = "SELECT * FROM courses " +
                "INNER JOIN teachers ON courses.teacher_course = teachers.contract_teacher " +
                "WHERE " + field + " = ?";
        List<Course> courses = new ArrayList<>();

        try (PreparedStatement ps = DBConnector.getConnection().prepareStatement(sql)) {
            switch (field) {
                case ID_COURSE -> ps.setObject(1, UUID.fromString(value));
                default -> ps.setString(1, value);
            }

            try (ResultSet rs = ps.executeQuery()) {
                while (rs.next()) {
                    Course course = getCourseFromResultSet(rs);
                    courses.add(course);
                }
            }
        } catch (SQLException e) {
            System.out.println("Ошибка при получении курсов: " + e.getMessage());
            e.printStackTrace();
            return null;
        }

        if (courses.isEmpty()) {
            return null;
        } else {
            return courses;
        }
    }

    public boolean save(Course course) {
        if (CheckInDB.teacherNotInDB(course)) { return false; }

        String sql = "INSERT INTO courses (id_course, title_course, description_course, teacher_course) VALUES (?, ?, ?, ?)";

        try (PreparedStatement ps = DBConnector.getConnection().prepareStatement(sql)) {

            setCourseForPreparedStatement(course, ps);
            ps.executeUpdate();
            return true;
        } catch (SQLException e) {
            if (e.getErrorCode() == 1062) {
                System.out.println("Такой курс уже есть в базе данных");
            } else {
                System.out.println("Ошибка при добавлении курса: " + e.getMessage());
            }
            return false;
        }
    }

    public boolean save(List<Course> courses) {
        if (CheckInDB.teachersNotInDB(courses)) {
            return false;
        }

        String sql = "INSERT INTO courses (id_course, title_course, description_course, teacher_course) VALUES (?, ?, ?, ?)";

        try (PreparedStatement ps = DBConnector.getConnection().prepareStatement(sql)) {
            for (Course course : courses) {
                setCourseForPreparedStatement(course, ps);
                ps.addBatch();
            }

            ps.executeBatch();
            return true;
        } catch (SQLException e) {
            System.out.println("Ошибка при добавлении курсов: " + e.getMessage());
            return false;
        }
    }

    public boolean delete(Course course) {
        String sql = "DELETE FROM courses WHERE id_course = ?";

        try (PreparedStatement ps = DBConnector.getConnection().prepareStatement(sql)) {
            ps.setObject(1, course.getId());
            return ps.executeUpdate() > 0;
        } catch (SQLException e) {
            System.out.println("Ошибка при удалении курса: " + e.getMessage());
            return false;
        }
    }

    public boolean delete(List<Course> courses) {
        if (courses.isEmpty()) {
            return false;
        }

        String sql = "DELETE FROM courses WHERE id_course = ?";

        try (PreparedStatement ps = DBConnector.getConnection().prepareStatement(sql)) {

            for (Course course : courses) {
                ps.setObject(1, course.getId());
                ps.addBatch();
            }
            ps.executeBatch();
            return true;
        } catch (SQLException e) {
            System.out.println("Ошибка при удалении курсов: " + e.getMessage());
            return false;
        }
    }

    public boolean update(Course course, String value, FieldsOfCourse field) {
        if (CheckInDB.teacherNotInDB(course)) { return false; }

        if (field == FieldsOfCourse.TEACHER_COURSE) {
            if (CheckInDB.teacherNotInDB(value)) {
                return false;
            }
            if (CheckInDB.teacherUniqueCourses(value)) {
                return false;
            }
        }

        String sql = "UPDATE courses SET " + field + " = ? WHERE id_course = ?";

        try (PreparedStatement ps = DBConnector.getConnection().prepareStatement(sql)) {
            ps.setString(1, value);
            ps.setObject(2, course.getId());
            int rowsAffected = ps.executeUpdate();
            if (rowsAffected > 0) {
                switch (field) {
                    case ID_COURSE -> course.setId(UUID.fromString(value));
                    case TITLE_COURSE -> course.setTitle(value);
                    case DESCRIPTION_COURSE -> course.setDescription(value);
                    case TEACHER_COURSE -> course.setTeacher((new TeachersRepository()).findByContract(value));
                }
                return true;
            } else {
                return false;
            }
        } catch (SQLException e) {
            System.out.println("Ошибка при обновлении курса: " + e.getMessage());
            e.printStackTrace();
            return false;
        }
    }
}