Penyuntingan soalan ujian dan fungsi pengurusan sistem peperiksaan dalam talian yang ditulis dalam Java

CREATE TABLE tb_question (
    id int PRIMARY KEY AUTO_INCREMENT,
    content VARCHAR(255) NOT NULL,
    option_a VARCHAR(100),
    option_b VARCHAR(100),
    option_c VARCHAR(100),
    option_d VARCHAR(100),
    answer VARCHAR(10),
    category_id int
);

CREATE TABLE tb_category (
    id int PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(50) NOT NULL
);

public class Question {
    private int id;
    private String content;
    private String optionA;
    private String optionB;
    private String optionC;
    private String optionD;
    private String answer;
    private int categoryId;

    // 省略构造方法和Getter/Setter方法
}

import java.sql.*;

public class QuestionDao {
    private Connection conn;

    public QuestionDao() {
        // 连接数据库
        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_exam", "username", "password");
    }

    public int addQuestion(Question question) throws SQLException {
        PreparedStatement stmt = conn.prepareStatement("INSERT INTO tb_question(content, option_a, option_b, option_c, option_d, answer, category_id) VALUES (?, ?, ?, ?, ?, ?, ?)", Statement.RETURN_GENERATED_KEYS);
        stmt.setString(1, question.getContent());
        stmt.setString(2, question.getOptionA());
        stmt.setString(3, question.getOptionB());
        stmt.setString(4, question.getOptionC());
        stmt.setString(5, question.getOptionD());
        stmt.setString(6, question.getAnswer());
        stmt.setInt(7, question.getCategoryId());

        int rowsAffected = stmt.executeUpdate();

        if (rowsAffected == 1) {
            ResultSet rs = stmt.getGeneratedKeys();
            if (rs.next()) {
                question.setId(rs.getInt(1));
            }
        }

        return rowsAffected;
    }

    // 省略其他数据库操作方法
}

import java.sql.SQLException;

public class QuestionManager {
    private QuestionDao questionDao;

    public QuestionManager() {
        questionDao = new QuestionDao();
    }

    public int addQuestion(Question question) {
        try {
            return questionDao.addQuestion(question);
        } catch (SQLException e) {
            e.printStackTrace();
        }

        return 0;
    }

    // 省略其他试题编辑和管理功能的方法
}