删除选课码字段，直接使用班级码加入班级

src/main/java/com/njuzr/eaibackend/controller/CourseController.java

@@ -266,17 +266,19 @@ public class CourseController {
      * 新的选课接口，通过班级码将学生加入对应班级
      * @param studentId
      * @param enrollDTO
+     * @param classCode
      * @return
      */
     @PreAuthorize("hasRole('STUDENT')")
     @PostMapping("/enroll")
     public MyResponse enrollByClassCode(
             @AuthenticationPrincipal(expression = "id") Long studentId,
-            @RequestBody EnrollDTO enrollDTO
+            @RequestBody EnrollDTO enrollDTO,
+            @RequestParam String classCode
     ) {
         try {
             enrollDTO.setStudentId(studentId);
-            courseService.enrollByClassCode(enrollDTO);
+            courseService.enrollByClassCode(enrollDTO, classCode);
             return MyResponse.success("选课成功");
         }
         catch (MyException e){

src/main/java/com/njuzr/eaibackend/dto/course/EnrollDTO.java

@@ -14,5 +14,4 @@ import lombok.Data;
 public class EnrollDTO {
     private Long studentId;
     private Long courseId;
-    private String enrollCode;
 }

src/main/java/com/njuzr/eaibackend/service/CourseService.java

@@ -35,7 +35,7 @@ public interface CourseService {
     void enroll(EnrollDTO enrollDTO);
 
     // 通过班级码选课
-    void enrollByClassCode(EnrollDTO enrollDTO);
+    void enrollByClassCode(EnrollDTO enrollDTO, String classCode);
 
     IPage<UserVO> getEnrollmentsByCourse(Page<User> page, Long teacherId, Long courseId);
 

src/main/java/com/njuzr/eaibackend/service/impl/CourseServiceImpl.java

@@ -364,9 +364,8 @@ public class CourseServiceImpl implements CourseService {
 
     @Override
     @Transactional
-    public void enrollByClassCode(EnrollDTO enrollDTO) {
+    public void enrollByClassCode(EnrollDTO enrollDTO, String classCode) {
         // 根据班级码查询班级信息
-        String classCode = enrollDTO.getEnrollCode();
         QueryWrapper<Class> classWrapper = new QueryWrapper<>();
         classWrapper.eq("class_code", classCode);
         Class targetClass = classMapper.selectOne(classWrapper);