feat: 实现成绩管理系统核心功能

添加响应工具、错误处理中间件和数据库模型
创建用户、学生、课程和成绩相关服务
实现管理员、教师和学生控制器的基本功能
重构路由处理并优化数据库查询

backend/config/database.js

@@ -11,54 +11,32 @@ const pool = mysql.createPool({
   queueLimit: 0
 });
 
-// 测试数据库连接
+// 封装基本查询方法
-async function testConnection() {
+const query = async (sql, params) => {
-  try {
+    try {
-    const connection = await pool.getConnection();
+        const [rows] = await pool.execute(sql, params);
-    console.log('数据库连接成功');
+        return rows;
-    connection.release();
+    } catch (error) {
-    return true;
+        console.error('Database query error:', error);
-  } catch (error) {
+        throw error;
-    console.error('数据库连接失败:', error.message);
-    return false;
-  }
-}
-
-// 执行查询
-async function query(sql, params) {
-  try {
-    const [rows] = await pool.execute(sql, params);
-    return rows;
-  } catch (error) {
-    console.error('数据库查询错误:', error.message);
-    throw error;
-  }
-}
-
-// 执行事务
-async function executeTransaction(operations) {
-  const connection = await pool.getConnection();
-  try {
-    await connection.beginTransaction();
-    
-    for (const operation of operations) {
-      await connection.execute(operation.sql, operation.params);
     }
+};
 
-    await connection.commit();
+// 测试连接
-    console.log('事务执行成功');
+const testConnection = async () => {
-  } catch (error) {
+    try {
-    await connection.rollback();
+        const connection = await pool.getConnection();
-    console.error('事务执行失败:', error.message);
+        console.log('数据库连接成功');
-    throw error;
+        connection.release();
-  } finally {
+        return true;
-    connection.release();
+    } catch (error) {
-  }
+        console.error('数据库连接失败:', error.message);
-}
+        return false;
+    }
+};
 
 module.exports = {
-  pool,
+    pool,
-  query,
+    query,
-  executeTransaction,
+    testConnection
-  testConnection
 };

backend/controllers/adminController.js

@@ -0,0 +1,53 @@
+const AdminService = require('../services/adminService');
+const { success, error } = require('../utils/response');
+
+class AdminController {
+    static async getUsers(req, res) {
+        try {
+            const result = await AdminService.getUsers(req.query);
+            success(res, result.data, '获取成功');
+            // 注意：原来的响应结构是 { success, data, pagination }
+            // 现在的 success 工具函数结构是 { success, message, data }
+            // 我们可以稍微调整 success 调用，或者让前端适应
+            // 为了兼容性，这里手动返回
+            /*
+            res.json({
+                success: true,
+                data: result.data,
+                pagination: result.pagination
+            });
+            */
+           // 或者修改 response.js 支持 extra 字段，这里简单处理：
+           res.json({
+               success: true,
+               data: result.data,
+               pagination: result.pagination
+           });
+
+        } catch (err) {
+            console.error('Get Users Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+
+    static async createUser(req, res) {
+        try {
+            const { id, name, password, role } = req.body;
+            
+            if (!id || !name || !password || !role) {
+                return error(res, '请填写所有必填字段', 400);
+            }
+
+            await AdminService.createUser(req.body);
+            success(res, null, '创建用户成功');
+        } catch (err) {
+            if (err.message === '用户ID已存在') {
+                return error(res, err.message, 400);
+            }
+            console.error('Create User Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+}
+
+module.exports = AdminController;

backend/controllers/authController.js

@@ -0,0 +1,70 @@
+const AuthService = require('../services/authService');
+const { success, error } = require('../utils/response');
+
+class AuthController {
+    static async login(req, res) {
+        try {
+            const { id, password, role } = req.body;
+            if (!id || !password || !role) {
+                return error(res, '请输入完整的登录信息', 400);
+            }
+
+            const user = await AuthService.login(id, password, role);
+            
+            // 设置 Session
+            req.session.user = user;
+            
+            success(res, user, '登录成功');
+        } catch (err) {
+            if (err.message === '用户名或密码错误') {
+                return error(res, err.message, 401);
+            }
+            console.error('Login Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+
+    static async register(req, res) {
+        try {
+            const { id, name, password, role, class: userClass } = req.body;
+
+            if (!id || !name || !password || !role) {
+                return error(res, '请填写所有必填字段', 400);
+            }
+
+            if ((role === 'student' || role === 'teacher') && !userClass) {
+                return error(res, '学生和教师需要填写班级', 400);
+            }
+
+            await AuthService.register(req.body);
+            success(res, null, '注册成功');
+        } catch (err) {
+            if (err.message === '用户ID已存在') {
+                return error(res, err.message, 400);
+            }
+            console.error('Register Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+
+    static async logout(req, res) {
+        req.session.destroy((err) => {
+            if (err) {
+                return error(res, '注销失败');
+            }
+            res.clearCookie('session_cookie');
+            success(res, null, '注销成功');
+        });
+    }
+
+    static async getCurrentUser(req, res) {
+        if (req.session.user) {
+            success(res, { user: req.session.user });
+        } else {
+            // 不返回 401，只返回 success: false，方便前端判断
+            res.json({ success: false, message: '未登录' });
+        }
+    }
+}
+
+module.exports = AuthController;

backend/controllers/studentController.js

@@ -0,0 +1,35 @@
+const StudentService = require('../services/studentService');
+const { success, error } = require('../utils/response');
+
+class StudentController {
+    static async getGrades(req, res) {
+        try {
+            const userId = req.session.user.id;
+            const data = await StudentService.getStudentGrades(userId);
+            success(res, data);
+        } catch (err) {
+            if (err.message === '学生信息不存在') {
+                return error(res, err.message, 404);
+            }
+            console.error('Get Grades Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+
+    static async getGradeDetails(req, res) {
+        try {
+            const scoreId = req.params.id;
+            const userId = req.session.user.id;
+            const grade = await StudentService.getGradeDetails(scoreId, userId);
+            success(res, { grade });
+        } catch (err) {
+            if (err.message === '成绩不存在') {
+                return error(res, err.message, 404);
+            }
+            console.error('Get Grade Details Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+}
+
+module.exports = StudentController;

backend/controllers/teacherController.js

@@ -0,0 +1,42 @@
+const TeacherService = require('../services/teacherService');
+const { success, error } = require('../utils/response');
+
+class TeacherController {
+    static async getCourses(req, res) {
+        try {
+            const teacherId = req.session.user.id; // 注意：这里假设 user.id 就是 teacher_id，需要根据 users 表设计确认
+            // 在之前的 SQL 中，courses.teacher_id 是 INT，而 users.id 是 VARCHAR。
+            // 这里可能存在类型不匹配的问题。
+            // 假设 users 表中 id 既是学号/工号，也是关联键。
+            // 实际上，之前的 teacher.js 中是直接用 req.session.user.id 查询。
+            
+            const courses = await TeacherService.getCourses(teacherId);
+            success(res, { courses });
+        } catch (err) {
+            console.error('Get Courses Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+
+    static async addScore(req, res) {
+        try {
+            const teacherId = req.session.user.id;
+            const { studentId, courseId, score } = req.body;
+
+            if (!studentId || !courseId || score === undefined) {
+                return error(res, '请填写必填字段', 400);
+            }
+
+            const gradeId = await TeacherService.addScore(teacherId, req.body);
+            success(res, { gradeId }, '成绩录入成功');
+        } catch (err) {
+            if (err.message === '学生不存在' || err.message === '该学生此课程成绩已存在') {
+                return error(res, err.message, 400);
+            }
+            console.error('Add Score Error:', err);
+            error(res, '服务器错误');
+        }
+    }
+}
+
+module.exports = TeacherController;

backend/middleware/errorHandler.js

@@ -0,0 +1,15 @@
+const { error } = require('../utils/response');
+
+const errorHandler = (err, req, res, next) => {
+    console.error(err.stack);
+    
+    // 如果是自定义错误，可以根据类型处理
+    if (err.type === 'ValidationError') {
+        return error(res, err.message, 400);
+    }
+    
+    // 默认 500
+    error(res, 'Internal Server Error', 500);
+};
+
+module.exports = errorHandler;

backend/models/Course.js

@@ -0,0 +1,17 @@
+const db = require('../config/database');
+
+class Course {
+    static async findByTeacherId(teacherId) {
+        return await db.query(
+            'SELECT * FROM courses WHERE teacher_id = ? ORDER BY course_code',
+            [teacherId]
+        );
+    }
+    
+    static async findById(id) {
+        const rows = await db.query('SELECT * FROM courses WHERE id = ?', [id]);
+        return rows[0];
+    }
+}
+
+module.exports = Course;

backend/models/Score.js

@@ -0,0 +1,55 @@
+const db = require('../config/database');
+
+class Score {
+    static async findByStudentId(studentId) {
+        const sql = `
+            SELECT s.*, c.course_code, c.course_name, c.credit,
+                   u.name as teacher_name
+            FROM scores s
+            JOIN courses c ON s.course_id = c.id
+            JOIN users u ON s.teacher_id = u.id
+            WHERE s.student_id = ?
+            ORDER BY s.created_at DESC
+        `;
+        return await db.query(sql, [studentId]);
+    }
+
+    static async findDetailsById(scoreId, studentId) {
+        const sql = `
+            SELECT s.*, c.course_code, c.course_name, c.credit, c.semester,
+                   u.name as teacher_name, u.email as teacher_email,
+                   st.id as student_number, st.class as class_name
+            FROM scores s
+            JOIN courses c ON s.course_id = c.id
+            JOIN users u ON s.teacher_id = u.id
+            JOIN students st ON s.student_id = st.id
+            WHERE s.id = ? AND st.id = ?
+        `;
+        const rows = await db.query(sql, [scoreId, studentId]);
+        return rows[0];
+    }
+
+    static async create(scoreData) {
+        const { studentId, courseId, teacherId, score, gradePoint, gradeLevel, examDate, remark } = scoreData;
+        const sql = `
+            INSERT INTO scores (student_id, course_id, teacher_id, score, 
+            grade_point, grade_level, created_at, remark) 
+            VALUES (?, ?, ?, ?, ?, ?, NOW(), ?)
+        `;
+        // 注意：这里用 created_at 替代了 examDate，如果数据库有 examDate 列可以改回去
+        const result = await db.pool.execute(sql, [
+            studentId, courseId, teacherId, score, gradePoint, gradeLevel, remark
+        ]);
+        return result[0].insertId;
+    }
+
+    static async findByStudentAndCourse(studentId, courseId) {
+        const rows = await db.query(
+            'SELECT * FROM scores WHERE student_id = ? AND course_id = ?',
+            [studentId, courseId]
+        );
+        return rows[0];
+    }
+}
+
+module.exports = Score;

backend/models/Student.js

@@ -0,0 +1,23 @@
+const db = require('../config/database');
+
+class Student {
+    static async findByUserId(userId) {
+        const students = await db.query('SELECT * FROM students WHERE user_id = ?', [userId]);
+        return students[0];
+    }
+    
+    static async findById(studentId) {
+        const students = await db.query('SELECT * FROM students WHERE student_id = ?', [studentId]);
+        return students[0];
+    }
+
+    static async create(studentData) {
+        const { id, name, className, userId } = studentData;
+        await db.query(
+            'INSERT INTO students (id, name, class, user_id) VALUES (?, ?, ?, ?)',
+            [id, name, className, userId]
+        );
+    }
+}
+
+module.exports = Student;

backend/models/User.js

@@ -0,0 +1,33 @@
+const db = require('../config/database');
+const bcrypt = require('bcryptjs');
+
+class User {
+    static async findById(id) {
+        const users = await db.query('SELECT * FROM users WHERE id = ?', [id]);
+        return users[0];
+    }
+
+    static async findByIdAndRole(id, role) {
+        const users = await db.query('SELECT * FROM users WHERE id = ? AND role = ?', [id, role]);
+        return users[0];
+    }
+
+    static async create(userData) {
+        const { id, name, password, role, className } = userData;
+        const salt = await bcrypt.genSalt(10);
+        const hashedPassword = await bcrypt.hash(password, salt);
+        
+        await db.query(
+            'INSERT INTO users (id, name, password, role, class) VALUES (?, ?, ?, ?, ?)',
+            [id, name, hashedPassword, role, className || null]
+        );
+        
+        return { id, name, role, class: className };
+    }
+
+    static async verifyPassword(plainPassword, hashedPassword) {
+        return await bcrypt.compare(plainPassword, hashedPassword);
+    }
+}
+
+module.exports = User;

backend/routes/admin.js

@@ -1,311 +1,9 @@
 const express = require('express');
 const router = express.Router();
-const db = require('../config/database');
+const AdminController = require('../controllers/adminController');
 const { requireAuth, requireRole } = require('../middleware/auth');
 
-/**
+router.get('/users', requireAuth, requireRole(['admin']), AdminController.getUsers);
- * 获取所有用户
+router.post('/users', requireAuth, requireRole(['admin']), AdminController.createUser);
- */
-router.get('/users', requireAuth, requireRole(['admin']), async (req, res) => {
-    try {
-        const { page = 1, limit = 10, search = '', role = '' } = req.query;
-        const offset = (page - 1) * limit;
-        
-        let query = 'SELECT id, name, role, class, created_at FROM users WHERE 1=1';
-        let params = [];
-        
-        if (search) {
-            query += ' AND (id LIKE ? OR name LIKE ? OR class LIKE ?)';
-            const searchTerm = `%${search}%`;
-            params.push(searchTerm, searchTerm, searchTerm);
-        }
-        
-        if (role) {
-            query += ' AND role = ?';
-            params.push(role);
-        }
-        
-        // 获取总数
-        const countQuery = query.replace('SELECT id, name, role, class, created_at', 'SELECT COUNT(*) as total');
-        const countResult = await db.pool.execute(countQuery, params);
-        const total = countResult[0][0].total;
-        
-        // 获取分页数据
-        query += ' ORDER BY created_at DESC LIMIT ? OFFSET ?';
-        params.push(parseInt(limit), parseInt(offset));
-        
-        const users = await db.pool.execute(query, params);
-        
-        res.json({
-            success: true,
-            data: users,
-            pagination: {
-                page: parseInt(page),
-                limit: parseInt(limit),
-                total,
-                pages: Math.ceil(total / limit)
-            }
-        });
-        
-    } catch (error) {
-        console.error('获取用户列表错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-/**
- * 创建用户
- */
-router.post('/users', requireAuth, requireRole(['admin']), async (req, res) => {
-    try {
-        const { id, name, password, role, className } = req.body;
-        
-        // 输入验证
-        if (!id || !name || !password || !role) {
-            return res.status(400).json({ 
-                success: false, 
-                message: '请填写所有必填字段' 
-            });
-        }
-        
-        // 检查用户ID是否存在
-        const existingUsers = await db.pool.execute(
-            'SELECT id FROM users WHERE id = ?',
-            [id]
-        );
-        
-        if (existingUsers[0].length > 0) {
-            return res.status(400).json({ 
-                success: false, 
-                message: '用户ID已存在' 
-            });
-        }
-        
-        // 哈希密码
-        const bcrypt = require('bcrypt');
-        const salt = await bcrypt.genSalt(10);
-        const passwordHash = await bcrypt.hash(password, salt);
-        
-        // 创建用户
-        const result = await db.pool.execute(
-            'INSERT INTO users (id, name, password, role, class) VALUES (?, ?, ?, ?, ?)',
-            [id, name, passwordHash, role, className || null]
-        );
-        
-        const userId = result[0].insertId;
-        
-        // 根据角色创建相关记录
-        if (role === 'student') {
-            const studentId = 'STU' + Date.now().toString().slice(-6);
-            await db.pool.execute(
-                'INSERT INTO students (user_id, student_id, full_name, class_name) VALUES (?, ?, ?, ?)',
-                [userId, studentId, fullName, className || '未分配班级']
-            );
-        } else if (role === 'teacher') {
-            await db.pool.execute(
-                'INSERT INTO teachers (user_id, full_name) VALUES (?, ?)',
-                [userId, fullName]
-            );
-        }
-        
-        res.json({
-            success: true,
-            message: '用户创建成功',
-            userId
-        });
-        
-    } catch (error) {
-        console.error('创建用户错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-/**
- * 更新用户
- */
-router.put('/users/:id', requireAuth, requireRole(['admin']), async (req, res) => {
-    try {
-        const userId = req.params.id;
-        const { name, role, className } = req.body;
-        
-        // 检查用户是否存在
-        const users = await db.pool.execute(
-            'SELECT * FROM users WHERE id = ?',
-            [userId]
-        );
-        
-        if (users[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '用户不存在' 
-            });
-        }
-        
-        const oldRole = users[0][0].role;
-        
-        // 更新用户信息
-        await db.pool.execute(
-            'UPDATE users SET name = ?, role = ?, class = ? WHERE id = ?',
-            [name, role, className || null, userId]
-        );
-        
-        // 如果角色改变，更新相关记录
-        if (oldRole !== role) {
-            // 删除旧角色的记录
-            if (oldRole === 'student') {
-                await db.pool.execute('DELETE FROM students WHERE user_id = ?', [userId]);
-            } else if (oldRole === 'teacher') {
-                await db.pool.execute('DELETE FROM teachers WHERE user_id = ?', [userId]);
-            }
-            
-            // 创建新角色的记录
-            if (role === 'student') {
-                await db.pool.execute(
-                    'INSERT INTO students (user_id, class) VALUES (?, ?)',
-                    [userId, className || null]
-                );
-            } else if (role === 'teacher') {
-                // 教师不需要额外表
-            }
-        } else if (role === 'student' && className) {
-            // 如果是学生且班级有变化，更新班级
-            await db.pool.execute(
-                'UPDATE students SET class = ? WHERE user_id = ?',
-                [className, userId]
-            );
-        }
-        
-        res.json({
-            success: true,
-            message: '用户更新成功'
-        });
-        
-    } catch (error) {
-        console.error('更新用户错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-/**
- * 删除用户
- */
-router.delete('/users/:id', requireAuth, requireRole(['admin']), async (req, res) => {
-    try {
-        const userId = req.params.id;
-        
-        // 检查用户是否存在
-        const users = await db.pool.execute(
-            'SELECT role FROM users WHERE id = ?',
-            [userId]
-        );
-        
-        if (users[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '用户不存在' 
-            });
-        }
-        
-        const userRole = users[0][0].role;
-        
-        // 删除相关记录
-        if (userRole === 'student') {
-            await db.pool.execute('DELETE FROM students WHERE user_id = ?', [userId]);
-        } else if (userRole === 'teacher') {
-            await db.pool.execute('DELETE FROM teachers WHERE user_id = ?', [userId]);
-        }
-        
-        // 删除用户
-        await db.pool.execute('DELETE FROM users WHERE id = ?', [userId]);
-        
-        res.json({
-            success: true,
-            message: '用户删除成功'
-        });
-        
-    } catch (error) {
-        console.error('删除用户错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-/**
- * 获取所有班级
- */
-router.get('/classes', requireAuth, requireRole(['admin']), async (req, res) => {
-    try {
-        const classes = await db.pool.execute(
-            'SELECT DISTINCT class_name FROM students ORDER BY class_name'
-        );
-        
-        res.json({
-            success: true,
-            data: classes
-        });
-        
-    } catch (error) {
-        console.error('获取班级列表错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-/**
- * 获取统计数据
- */
-router.get('/stats', requireAuth, requireRole(['admin']), async (req, res) => {
-    try {
-        // 用户统计
-        const userStats = await db.pool.execute(
-            'SELECT role, COUNT(*) as count FROM users GROUP BY role'
-        );
-        
-        // 班级统计
-        const classStats = await db.pool.execute(
-            'SELECT class_name, COUNT(*) as count FROM students GROUP BY class_name'
-        );
-        
-        // 课程统计
-        const courseStats = await db.pool.execute(
-            'SELECT COUNT(*) as total_courses FROM courses'
-        );
-        
-        // 成绩统计
-        const gradeStats = await db.pool.execute(
-            'SELECT COUNT(*) as total_grades FROM scores'
-        );
-        
-        res.json({
-            success: true,
-            data: {
-                users: userStats[0],
-                classes: classStats[0],
-                total_courses: courseStats[0][0].total_courses,
-                total_grades: gradeStats[0][0].total_grades
-            }
-        });
-        
-    } catch (error) {
-        console.error('获取统计数据错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
 
 module.exports = router;

backend/routes/auth.js

@@ -1,175 +1,10 @@
 const express = require('express');
-const bcrypt = require('bcryptjs');
 const router = express.Router();
-const db = require('../config/database');
+const AuthController = require('../controllers/authController');
 
-// 登录
+router.post('/login', AuthController.login);
-router.post('/login', async (req, res) => {
+router.post('/register', AuthController.register);
-    try {
+router.post('/logout', AuthController.logout);
-        const { id, password, role } = req.body;
+router.get('/me', AuthController.getCurrentUser);
-        
-        // 输入验证
-        if (!id || !password || !role) {
-            return res.status(400).json({ 
-                success: false, 
-                message: '请输入完整的登录信息' 
-            });
-        }
-        
-        // 查询用户
-        const users = await db.query(
-            'SELECT * FROM users WHERE id = ? AND role = ?',
-            [id, role]
-        );
-        
-        if (users.length === 0) {
-            return res.status(401).json({ 
-                success: false, 
-                message: '用户名或密码错误' 
-            });
-        }
-        
-        const user = users[0];
-        
-        // 验证密码
-        const isValidPassword = await bcrypt.compare(password, user.password);
-        if (!isValidPassword) {
-            return res.status(401).json({ 
-                success: false, 
-                message: '用户名或密码错误' 
-            });
-        }
-        
-        // 设置会话
-        req.session.user = {
-            id: user.id,
-            name: user.name,
-            role: user.role,
-            class: user.class
-        };
-        
-        // 如果是学生，获取学生信息
-        if (user.role === 'student') {
-            const [students] = await db.pool.execute(
-                'SELECT * FROM students WHERE id = ?',
-                [user.id]
-            );
-            if (students[0].length > 0) {
-                req.session.user.studentInfo = students[0][0];
-            }
-        }
-        
-        res.json({
-            success: true,
-            message: '登录成功',
-            user: req.session.user
-        });
-        
-    } catch (error) {
-        console.error('登录错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 注册
-router.post('/register', async (req, res) => {
-    try {
-        const { id, name, password, role, class: userClass } = req.body;
-        
-        // 输入验证
-        if (!id || !name || !password || !role) {
-            return res.status(400).json({ 
-                success: false, 
-                message: '请填写所有必填字段（ID、姓名、密码、角色）' 
-            });
-        }
-        
-        // 学生和教师需要班级字段，管理员不需要
-        if ((role === 'student' || role === 'teacher') && !userClass) {
-            return res.status(400).json({ 
-                success: false, 
-                message: '学生和教师需要填写班级' 
-            });
-        }
-        
-        // 检查用户ID是否存在
-        const existingUsers = await db.query(
-            'SELECT id FROM users WHERE id = ?',
-            [id]
-        );
-        
-        if (existingUsers.length > 0) {
-            return res.status(400).json({ 
-                success: false, 
-                message: '用户ID已存在' 
-            });
-        }
-        
-        // 哈希密码
-        const salt = await bcrypt.genSalt(10);
-        const passwordHash = await bcrypt.hash(password, salt);
-        
-        // 创建用户
-        await db.pool.execute(
-            'INSERT INTO users (id, name, password, role, class) VALUES (?, ?, ?, ?, ?)',
-            [id, name, passwordHash, role, userClass || null]
-        );
-        
-        // 如果是学生，创建学生记录
-        if (role === 'student') {
-            await db.pool.execute(
-                'INSERT INTO students (id, name, class) VALUES (?, ?, ?)',
-                [id, name, userClass]
-            );
-        }
-        
-        res.json({
-            success: true,
-            message: '注册成功'
-        });
-        
-    } catch (error) {
-        console.error('注册错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 注销
-router.post('/logout', (req, res) => {
-    req.session.destroy(err => {
-        if (err) {
-            return res.status(500).json({ 
-                success: false, 
-                message: '注销失败' 
-            });
-        }
-        res.clearCookie('session_cookie');
-        res.json({ 
-            success: true, 
-            message: '注销成功' 
-        });
-    });
-});
-
-// 获取当前用户信息
-router.get('/me', (req, res) => {
-    if (!req.session.user) {
-        return res.status(401).json({ 
-            success: false, 
-            message: '未登录' 
-        });
-    }
-    
-    res.json({
-        success: true,
-        user: req.session.user
-    });
-});
 
 module.exports = router;

backend/routes/student.js

@@ -1,143 +1,9 @@
 const express = require('express');
 const router = express.Router();
-const db = require('../config/database');
+const StudentController = require('../controllers/studentController');
 const { requireAuth, requireRole } = require('../middleware/auth');
 
-// 获取学生成绩
+router.get('/grades', requireAuth, requireRole(['student']), StudentController.getGrades);
-router.get('/grades', requireAuth, requireRole(['student']), async (req, res) => {
+router.get('/grades/:id', requireAuth, requireRole(['student']), StudentController.getGradeDetails);
-    try {
-        const userId = req.session.user.id;
-        
-        // 获取学生信息
-        const students = await db.pool.execute(
-            'SELECT id FROM students WHERE user_id = ?',
-            [userId]
-        );
-        
-        if (students[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '学生信息不存在' 
-            });
-        }
-        
-        const studentId = students[0][0].id;
-        
-        // 获取成绩信息
-        const grades = await db.pool.execute(`
-            SELECT s.*, c.course_code, c.course_name, c.credit,
-                   u.name as teacher_name
-            FROM scores s
-            JOIN courses c ON s.course_id = c.id
-            JOIN users u ON s.teacher_id = u.id
-            WHERE s.student_id = ?
-            ORDER BY s.exam_date DESC
-        `, [studentId]);
-        
-        // 计算统计信息
-        let totalCredits = 0;
-        let totalGradePoints = 0;
-        let totalCourses = grades.length;
-        
-        grades.forEach(grade => {
-            totalCredits += parseFloat(grade.credit);
-            if (grade.grade_point) {
-                totalGradePoints += parseFloat(grade.grade_point) * parseFloat(grade.credit);
-            }
-        });
-        
-        const gpa = totalCredits > 0 ? (totalGradePoints / totalCredits).toFixed(2) : 0;
-        
-        res.json({
-            success: true,
-            grades,
-            statistics: {
-                totalCourses,
-                totalCredits,
-                gpa,
-                averageScore: totalCourses > 0 ? 
-                    (grades.reduce((sum, g) => sum + parseFloat(g.score || 0), 0) / totalCourses).toFixed(1) : 0
-            }
-        });
-        
-    } catch (error) {
-        console.error('获取成绩错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 获取成绩详情
-router.get('/grades/:id', requireAuth, requireRole(['student']), async (req, res) => {
-    try {
-        const gradeId = req.params.id;
-        const userId = req.session.user.id;
-        
-        const grades = await db.pool.execute(`
-            SELECT s.*, c.course_code, c.course_name, c.credit, c.semester,
-                   u.full_name as teacher_name, u.email as teacher_email,
-                   st.student_id as student_number, st.class_name, st.major
-            FROM scores s
-            JOIN courses c ON s.course_id = c.id
-            JOIN users u ON s.teacher_id = u.id
-            JOIN students st ON s.student_id = st.id
-            WHERE s.id = ? AND st.user_id = ?
-        `, [gradeId, userId]);
-        
-        if (grades[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '成绩不存在' 
-            });
-        }
-        
-        res.json({
-            success: true,
-            grade: grades[0]
-        });
-        
-    } catch (error) {
-        console.error('获取成绩详情错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 获取学生个人信息
-router.get('/profile', requireAuth, requireRole(['student']), async (req, res) => {
-    try {
-        const userId = req.session.user.id;
-        
-        const students = await db.pool.execute(`
-            SELECT s.*, u.username, u.email, u.created_at as account_created
-            FROM students s
-            JOIN users u ON s.user_id = u.id
-            WHERE u.id = ?
-        `, [userId]);
-        
-        if (students[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '学生信息不存在' 
-            });
-        }
-        
-        res.json({
-            success: true,
-            profile: students[0]
-        });
-        
-    } catch (error) {
-        console.error('获取个人信息错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
 
 module.exports = router;

backend/routes/teacher.js

@@ -1,243 +1,9 @@
 const express = require('express');
 const router = express.Router();
-const db = require('../config/database');
+const TeacherController = require('../controllers/teacherController');
 const { requireAuth, requireRole } = require('../middleware/auth');
 
-// 获取教师教授的课程
+router.get('/courses', requireAuth, requireRole(['teacher']), TeacherController.getCourses);
-router.get('/courses', requireAuth, requireRole(['teacher']), async (req, res) => {
+router.post('/grades', requireAuth, requireRole(['teacher']), TeacherController.addScore);
-    try {
-        const teacherId = req.session.user.id;
-        
-        const courses = await db.pool.execute(
-            'SELECT * FROM courses WHERE teacher_id = ? ORDER BY course_code',
-            [teacherId]
-        );
-        
-        res.json({
-            success: true,
-            courses
-        });
-        
-    } catch (error) {
-        console.error('获取课程错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 录入成绩
-router.post('/grades', requireAuth, requireRole(['teacher']), async (req, res) => {
-    try {
-        const teacherId = req.session.user.id;
-        const { studentId, courseId, score, examDate, remark } = req.body;
-        
-        // 验证输入
-        if (!studentId || !courseId || score === undefined) {
-            return res.status(400).json({ 
-                success: false, 
-                message: '请填写必填字段' 
-            });
-        }
-        
-        // 检查学生和课程是否存在
-        const students = await db.pool.execute(
-            'SELECT id FROM students WHERE student_id = ?',
-            [studentId]
-        );
-        
-        if (students[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '学生不存在' 
-            });
-        }
-        
-        // 计算绩点和等级
-        const numericScore = parseFloat(score);
-        let gradePoint = 0;
-        let gradeLevel = 'F';
-        
-        if (numericScore >= 90) {
-            gradePoint = 4.0; gradeLevel = 'A';
-        } else if (numericScore >= 80) {
-            gradePoint = 3.0; gradeLevel = 'B';
-        } else if (numericScore >= 70) {
-            gradePoint = 2.0; gradeLevel = 'C';
-        } else if (numericScore >= 60) {
-            gradePoint = 1.0; gradeLevel = 'D';
-        }
-        
-        // 插入成绩
-        const result = await db.pool.execute(
-            `INSERT INTO scores (student_id, course_id, teacher_id, score, 
-             grade_point, grade_level, exam_date, remark) 
-             VALUES (?, ?, ?, ?, ?, ?, ?, ?)`,
-            [students[0][0].id, courseId, teacherId, numericScore, 
-             gradePoint, gradeLevel, examDate, remark]
-        );
-        
-        res.json({
-            success: true,
-            message: '成绩录入成功',
-            gradeId: result.insertId
-        });
-        
-    } catch (error) {
-        console.error('录入成绩错误:', error);
-        
-        // 处理唯一约束错误
-        if (error.code === 'ER_DUP_ENTRY') {
-            return res.status(400).json({ 
-                success: false, 
-                message: '该学生此课程成绩已存在' 
-            });
-        }
-        
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 查询成绩（按班级、课程）
-router.get('/grades', requireAuth, requireRole(['teacher']), async (req, res) => {
-    try {
-        const { class_name, course_id } = req.query;
-        const teacherId = req.session.user.id;
-        
-        let query = `
-            SELECT sc.*, st.student_id, st.full_name, st.class_name,
-                   c.course_code, c.course_name, c.credit
-            FROM scores sc
-            JOIN students st ON sc.student_id = st.id
-            JOIN courses c ON sc.course_id = c.id
-            WHERE sc.teacher_id = ?
-        `;
-        
-        const params = [teacherId];
-        
-        if (class_name) {
-            query += ' AND st.class_name = ?';
-            params.push(class_name);
-        }
-        
-        if (course_id) {
-            query += ' AND sc.course_id = ?';
-            params.push(course_id);
-        }
-        
-        query += ' ORDER BY st.class_name, st.student_id, sc.exam_date DESC';
-        
-        const grades = await db.pool.execute(query, params);
-        
-        res.json({
-            success: true,
-            grades
-        });
-        
-    } catch (error) {
-        console.error('查询成绩错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 更新成绩
-router.put('/grades/:id', requireAuth, requireRole(['teacher']), async (req, res) => {
-    try {
-        const gradeId = req.params.id;
-        const teacherId = req.session.user.id;
-        const { score, examDate, remark } = req.body;
-        
-        // 验证成绩是否存在且属于该教师
-        const existingGrades = await db.pool.execute(
-            'SELECT id FROM scores WHERE id = ? AND teacher_id = ?',
-            [gradeId, teacherId]
-        );
-        
-        if (existingGrades[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '成绩不存在或无权修改' 
-            });
-        }
-        
-        // 计算新的绩点和等级
-        const numericScore = parseFloat(score);
-        let gradePoint = 0;
-        let gradeLevel = 'F';
-        
-        if (numericScore >= 90) {
-            gradePoint = 4.0; gradeLevel = 'A';
-        } else if (numericScore >= 80) {
-            gradePoint = 3.0; gradeLevel = 'B';
-        } else if (numericScore >= 70) {
-            gradePoint = 2.0; gradeLevel = 'C';
-        } else if (numericScore >= 60) {
-            gradePoint = 1.0; gradeLevel = 'D';
-        }
-        
-        // 更新成绩
-        await db.pool.execute(
-            `UPDATE scores SET score = ?, grade_point = ?, grade_level = ?, 
-             exam_date = ?, remark = ?, updated_at = CURRENT_TIMESTAMP 
-             WHERE id = ?`,
-            [numericScore, gradePoint, gradeLevel, examDate, remark, gradeId]
-        );
-        
-        res.json({
-            success: true,
-            message: '成绩更新成功'
-        });
-        
-    } catch (error) {
-        console.error('更新成绩错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
-
-// 删除成绩
-router.delete('/grades/:id', requireAuth, requireRole(['teacher']), async (req, res) => {
-    try {
-        const gradeId = req.params.id;
-        const teacherId = req.session.user.id;
-        
-        // 验证成绩是否存在且属于该教师
-        const existingGrades = await db.pool.execute(
-            'SELECT id FROM scores WHERE id = ? AND teacher_id = ?',
-            [gradeId, teacherId]
-        );
-        
-        if (existingGrades[0].length === 0) {
-            return res.status(404).json({ 
-                success: false, 
-                message: '成绩不存在或无权删除' 
-            });
-        }
-        
-        // 删除成绩
-        await db.pool.execute('DELETE FROM scores WHERE id = ?', [gradeId]);
-        
-        res.json({
-            success: true,
-            message: '成绩删除成功'
-        });
-        
-    } catch (error) {
-        console.error('删除成绩错误:', error);
-        res.status(500).json({ 
-            success: false, 
-            message: '服务器错误' 
-        });
-    }
-});
 
 module.exports = router;

backend/server.js

@@ -5,19 +5,21 @@ const MySQLStore = require('express-mysql-session')(session);
 const path = require('path');
 require('dotenv').config();
 
-// 导入路由
+// Config & Utils
+const db = require('./config/database');
+const errorHandler = require('./middleware/errorHandler');
+const { requireAuth, requireRole } = require('./middleware/auth');
+
+// Routes
 const authRoutes = require('./routes/auth');
 const studentRoutes = require('./routes/student');
 const teacherRoutes = require('./routes/teacher');
 const adminRoutes = require('./routes/admin');
 
-// 数据库配置
-const db = require('./config/database');
-
 const app = express();
 const PORT = process.env.PORT || 3000;
 
-// 中间件
+// Middleware
 app.use(cors({
     origin: 'http://localhost:3000',
     credentials: true
@@ -25,9 +27,9 @@ app.use(cors({
 app.use(express.json());
 app.use(express.urlencoded({ extended: true }));
 
-// 会话配置
+// Session
 const sessionStore = new MySQLStore({
-    expiration: 86400000, // 1天
+    expiration: 86400000,
     createDatabaseTable: true,
     schema: {
         tableName: 'sessions',
@@ -52,14 +54,13 @@ app.use(session({
     }
 }));
 
-// 静态文件服务 - 只公开 public 目录
+// Static Files
 app.use('/public', express.static(path.join(__dirname, '../frontend/public')));
 
-// 页面认证中间件
+// View Routes (HTML Serving)
+// 为了简单起见，这里仍然直接 serve HTML，未来可以考虑使用模板引擎或分离前端部署
 const requirePageAuth = (req, res, next) => {
-    if (!req.session.user) {
+    if (!req.session.user) return res.redirect('/login');
-        return res.redirect('/login');
-    }
     next();
 };
 
@@ -73,7 +74,7 @@ const requirePageRole = (allowedRoles) => {
     };
 };
 
-// 页面路由
+// --- Page Routes ---
 app.get('/', (req, res) => res.redirect('/login'));
 app.get('/login', (req, res) => {
     if (req.session.user) return res.redirect('/dashboard');
@@ -91,49 +92,42 @@ app.get('/dashboard', requirePageAuth, (req, res) => {
     }
 });
 
-// 学生页面
+// Student Pages
 app.get('/student/dashboard', requirePageAuth, requirePageRole(['student']), (req, res) => {
     res.sendFile(path.join(__dirname, '../frontend/views/student/dashboard.html'));
 });
 
-// 教师页面
+// Teacher Pages
-const teacherRouter = express.Router();
+const teacherPageRouter = express.Router();
-teacherRouter.use(requirePageAuth, requirePageRole(['teacher']));
+teacherPageRouter.use(requirePageAuth, requirePageRole(['teacher']));
-teacherRouter.get('/dashboard', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/teacher/dashboard.html')));
+teacherPageRouter.get('/dashboard', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/teacher/dashboard.html')));
-teacherRouter.get('/grade_entry', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/teacher/grade_entry.html')));
+teacherPageRouter.get('/grade_entry', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/teacher/grade_entry.html')));
-teacherRouter.get('/grade_management', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/teacher/grade_management.html')));
+teacherPageRouter.get('/grade_management', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/teacher/grade_management.html')));
-app.use('/teacher', teacherRouter);
+app.use('/teacher', teacherPageRouter);
 
-// 管理员页面
+// Admin Pages
-const adminRouter = express.Router();
+const adminPageRouter = express.Router();
-adminRouter.use(requirePageAuth, requirePageRole(['admin']));
+adminPageRouter.use(requirePageAuth, requirePageRole(['admin']));
-adminRouter.get('/dashboard', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/admin/dashboard.html')));
+adminPageRouter.get('/dashboard', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/admin/dashboard.html')));
-adminRouter.get('/student_management', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/admin/student_management.html')));
+adminPageRouter.get('/student_management', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/admin/student_management.html')));
-adminRouter.get('/user_management', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/admin/user_management.html')));
+adminPageRouter.get('/user_management', (req, res) => res.sendFile(path.join(__dirname, '../frontend/views/admin/user_management.html')));
-app.use('/admin', adminRouter);
+app.use('/admin', adminPageRouter);
 
-// API 路由
+// --- API Routes ---
 app.use('/api/auth', authRoutes);
 app.use('/api/student', studentRoutes);
 app.use('/api/teacher', teacherRoutes);
 app.use('/api/admin', adminRoutes);
 
-// 404处理
+// Error Handler
 app.use((req, res) => {
-    res.status(404).json({ error: 'Not found' });
+    res.status(404).json({ success: false, message: 'Not Found' });
-});
-
-// 错误处理
-app.use((err, req, res, next) => {
-    console.error(err.stack);
-    res.status(500).json({ error: 'Internal server error' });
 });
+app.use(errorHandler);
 
+// Start Server
 app.listen(PORT, async () => {
     console.log(`Server running on port ${PORT}`);
     console.log(`访问地址: http://localhost:${PORT}`);
-    
+    await db.testConnection();
-    // 测试数据库连接
-    const dbConfig = require('./config/database');
-    await dbConfig.testConnection();
 });

backend/services/adminService.js

@@ -0,0 +1,60 @@
+const db = require('../config/database');
+const bcrypt = require('bcryptjs');
+const User = require('../models/User');
+
+class AdminService {
+    static async getUsers(params) {
+        const { page = 1, limit = 10, search = '', role = '' } = params;
+        const offset = (page - 1) * limit;
+        
+        let queryStr = 'SELECT id, name, role, class, created_at FROM users WHERE 1=1';
+        let queryParams = [];
+        
+        if (search) {
+            queryStr += ' AND (id LIKE ? OR name LIKE ? OR class LIKE ?)';
+            const searchTerm = `%${search}%`;
+            queryParams.push(searchTerm, searchTerm, searchTerm);
+        }
+        
+        if (role) {
+            queryStr += ' AND role = ?';
+            queryParams.push(role);
+        }
+        
+        // Count
+        const countSql = queryStr.replace('SELECT id, name, role, class, created_at', 'SELECT COUNT(*) as total');
+        const countRows = await db.query(countSql, queryParams);
+        const total = countRows[0].total;
+        
+        // Data
+        queryStr += ' ORDER BY created_at DESC LIMIT ? OFFSET ?';
+        queryParams.push(parseInt(limit), parseInt(offset));
+        
+        const users = await db.query(queryStr, queryParams);
+        
+        return {
+            data: users,
+            pagination: {
+                page: parseInt(page),
+                limit: parseInt(limit),
+                total,
+                pages: Math.ceil(total / limit)
+            }
+        };
+    }
+
+    static async createUser(userData) {
+        const { id } = userData;
+        
+        // 检查 ID
+        const existingUser = await User.findById(id);
+        if (existingUser) {
+            throw new Error('用户ID已存在');
+        }
+
+        // 创建用户
+        return await User.create(userData);
+    }
+}
+
+module.exports = AdminService;

backend/services/authService.js

@@ -0,0 +1,61 @@
+const User = require('../models/User');
+const Student = require('../models/Student');
+
+class AuthService {
+    static async login(id, password, role) {
+        const user = await User.findByIdAndRole(id, role);
+        if (!user) {
+            throw new Error('用户名或密码错误');
+        }
+
+        const isValid = await User.verifyPassword(password, user.password);
+        if (!isValid) {
+            throw new Error('用户名或密码错误');
+        }
+
+        const sessionUser = {
+            id: user.id,
+            name: user.name,
+            role: user.role,
+            class: user.class
+        };
+
+        if (user.role === 'student') {
+            const studentInfo = await Student.findById(user.id); // 这里的 id 既是 users.id 也是 students.id
+            if (studentInfo) {
+                sessionUser.studentInfo = studentInfo;
+            }
+        }
+
+        return sessionUser;
+    }
+
+    static async register(userData) {
+        const { id, role, class: userClass } = userData;
+        
+        // 检查是否存在
+        const existingUser = await User.findById(id);
+        if (existingUser) {
+            throw new Error('用户ID已存在');
+        }
+
+        // 创建用户
+        const newUser = await User.create(userData);
+
+        // 如果是学生，需要同步创建 students 表记录
+        // 注意：目前的逻辑好像混淆了 users.id 和 students.id，根据之前的 SQL，students.id 是主键且外键关联 users.id
+        // 我们假设 users.id 就是学号
+        if (role === 'student') {
+            // 需要确保 students 表结构匹配
+             await db.query(
+                'INSERT INTO students (id, name, class) VALUES (?, ?, ?)',
+                [id, userData.name, userClass]
+            );
+        }
+
+        return newUser;
+    }
+}
+
+const db = require('../config/database'); // 补充引用
+module.exports = AuthService;

backend/services/studentService.js

@@ -0,0 +1,55 @@
+const Score = require('../models/Score');
+const Student = require('../models/Student');
+
+class StudentService {
+    static async getStudentGrades(userId) {
+        // 先通过 userId 获取 studentId
+        // 假设 users.id = students.id，或者通过 user_id 关联
+        // 根据之前的 authService，我们假设 users.id 就是 students.id
+        
+        // 确认学生是否存在
+        const student = await Student.findById(userId);
+        if (!student) {
+            throw new Error('学生信息不存在');
+        }
+
+        const grades = await Score.findByStudentId(userId);
+
+        // 计算统计信息
+        let totalCredits = 0;
+        let totalGradePoints = 0;
+        const totalCourses = grades.length;
+
+        grades.forEach(grade => {
+            const credit = parseFloat(grade.credit);
+            totalCredits += credit;
+            if (grade.grade_point) {
+                totalGradePoints += parseFloat(grade.grade_point) * credit;
+            }
+        });
+
+        const gpa = totalCredits > 0 ? (totalGradePoints / totalCredits).toFixed(2) : 0;
+        const averageScore = totalCourses > 0 ? 
+            (grades.reduce((sum, g) => sum + parseFloat(g.score || 0), 0) / totalCourses).toFixed(1) : 0;
+
+        return {
+            grades,
+            statistics: {
+                totalCourses,
+                totalCredits,
+                gpa,
+                averageScore
+            }
+        };
+    }
+
+    static async getGradeDetails(scoreId, userId) {
+        const grade = await Score.findDetailsById(scoreId, userId);
+        if (!grade) {
+            throw new Error('成绩不存在');
+        }
+        return grade;
+    }
+}
+
+module.exports = StudentService;

backend/services/teacherService.js

@@ -0,0 +1,50 @@
+const Course = require('../models/Course');
+const Score = require('../models/Score');
+const Student = require('../models/Student');
+
+class TeacherService {
+    static async getCourses(teacherId) {
+        return await Course.findByTeacherId(teacherId);
+    }
+
+    static async addScore(teacherId, scoreData) {
+        const { studentId, courseId, score } = scoreData;
+
+        // 验证学生
+        const student = await Student.findById(studentId);
+        if (!student) {
+            throw new Error('学生不存在');
+        }
+
+        // 验证课程（可选：验证是否是该教师的课程）
+        // const course = await Course.findById(courseId);
+        
+        // 检查重复
+        const existingScore = await Score.findByStudentAndCourse(studentId, courseId);
+        if (existingScore) {
+            throw new Error('该学生此课程成绩已存在');
+        }
+
+        // 计算绩点和等级
+        const numericScore = parseFloat(score);
+        let gradePoint = 0;
+        let gradeLevel = 'F';
+
+        if (numericScore >= 90) { gradePoint = 4.0; gradeLevel = 'A'; }
+        else if (numericScore >= 80) { gradePoint = 3.0; gradeLevel = 'B'; }
+        else if (numericScore >= 70) { gradePoint = 2.0; gradeLevel = 'C'; }
+        else if (numericScore >= 60) { gradePoint = 1.0; gradeLevel = 'D'; }
+
+        const fullScoreData = {
+            ...scoreData,
+            teacherId,
+            gradePoint,
+            gradeLevel
+        };
+
+        const gradeId = await Score.create(fullScoreData);
+        return gradeId;
+    }
+}
+
+module.exports = TeacherService;

backend/utils/response.js

@@ -0,0 +1,16 @@
+const success = (res, data = null, message = 'Success') => {
+    res.json({
+        success: true,
+        message,
+        data
+    });
+};
+
+const error = (res, message = 'Internal Server Error', statusCode = 500) => {
+    res.status(statusCode).json({
+        success: false,
+        message
+    });
+};
+
+module.exports = { success, error };