优化了students_dao里add_student_dao的报错逻辑。

students/dao/students_dao.py

@@ -62,9 +62,11 @@ def add_student_dao( s , db):
         phone = s.get("phone")
         s1_deleted = db.query( Students ).filter( Students.phone == phone ).first()
         if s1_deleted and s1_deleted.is_deleted == False:
-            return False
+            raise ValueError("该手机号已存在有效学生记录，请勿重复添加")
         if not phone:
-            return False
+            raise ValueError("手机号不能为空")
+        if not s.get("class_id") or not s.get("advisor_id"):
+            raise ValueError("班级ID和顾问ID必须已经存在才可以绑定")
         if s1_deleted and s1_deleted.is_deleted == True:
             s1_deleted.name = s.get("name")
             s1_deleted.age = s.get("age")
@@ -90,10 +92,14 @@ def add_student_dao( s , db):
             return s1_deleted
         s1 = Students( **s )
         db.add(s1)
+    except ValueError as e:
+        # 业务校验异常：回滚并返回错误信息
+        db.rollback()
+        return {"code": 400, "msg": str(e)}
     except Exception:
         # 这里可以加日志
         db.rollback()
-        return False
+        return {"code": 500, "msg": f"系统异常: {str(e)}"}
     else:
         db.commit()
         db.refresh(s1)