feat: add super-admin stu relationand difficuty

apps/user/cms.py

@@ -7,6 +7,7 @@
 import re
 
 from django.db import IntegrityError
+from django.db.models import Prefetch
 from rest_framework import viewsets, filters, status
 from rest_framework.decorators import action
 from rest_framework.parsers import MultiPartParser, FormParser
@@ -52,6 +53,12 @@ class CmsUserSerializer(serializers.ModelSerializer):
     """读取（列表 / 详情）。"""
     institution_name = serializers.CharField(source='institution.name', read_only=True, default=None)
     role_label = serializers.SerializerMethodField()
+    # 师生关系（仅取进行中 status=1）：
+    # - 医生：students = 名下学生 [{id, real_name, phone}]，teachers 为 None；
+    # - 学生：teachers = 带教医生 [{id, real_name, phone}]，students 为 None；
+    # - 其它角色：两者均为 None。
+    students = serializers.SerializerMethodField()
+    teachers = serializers.SerializerMethodField()
 
     class Meta:
         model = User
@@ -59,11 +66,33 @@ class CmsUserSerializer(serializers.ModelSerializer):
             'id', 'username', 'real_name', 'phone', 'role_type', 'role_label',
             'institution', 'institution_name',
             'gender', 'title_name', 'major', 'training_stage', 'status', 'created_at',
+            'students', 'teachers',
         ]
 
     def get_role_label(self, obj):
         return ROLE_LABEL_BY_CODE.get(obj.role_type, obj.role_type)
 
+    def get_students(self, obj):
+        if obj.role_type != 'doctor':
+            return None
+        # 优先使用 viewset 预取（prefetch）的关系，避免 N+1
+        rels = obj.teacher_relations.all() if 'teacher_relations' in getattr(obj, '_prefetched_objects_cache', {}) \
+            else TeacherStudentRelation.objects.filter(teacher=obj, status=1).select_related('student')
+        return [
+            {'id': r.student_id, 'real_name': r.student.real_name, 'phone': r.student.phone}
+            for r in rels if r.status == 1
+        ]
+
+    def get_teachers(self, obj):
+        if obj.role_type != 'student':
+            return None
+        rels = obj.student_relations.all() if 'student_relations' in getattr(obj, '_prefetched_objects_cache', {}) \
+            else TeacherStudentRelation.objects.filter(student=obj, status=1).select_related('teacher')
+        return [
+            {'id': r.teacher_id, 'real_name': r.teacher.real_name, 'phone': r.teacher.phone}
+            for r in rels if r.status == 1
+        ]
+
 
 class CmsUserWriteSerializer(serializers.ModelSerializer):
     """新增 / 编辑（role 必填）。"""
@@ -169,7 +198,17 @@ class CmsUserViewSet(viewsets.ModelViewSet):
     http_method_names = ['get', 'post', 'head', 'options']
 
     def get_queryset(self):
-        qs = User.objects.select_related('institution', 'department').all().order_by('-created_at')
+        # 预取师生关系（仅进行中 status=1）+ 对端用户，列表输出师生关系时避免 N+1
+        qs = (
+            User.objects.select_related('institution', 'department')
+            .prefetch_related(
+                Prefetch('teacher_relations',
+                         queryset=TeacherStudentRelation.objects.filter(status=1).select_related('student')),
+                Prefetch('student_relations',
+                         queryset=TeacherStudentRelation.objects.filter(status=1).select_related('teacher')),
+            )
+            .all().order_by('-created_at')
+        )
         user = self.request.user
         if is_super(user):
             return qs