From 1f8a7ea1c671d275a2cbcb47b4fd3e8fe9388215 Mon Sep 17 00:00:00 2001
From: tanglong <842690096@qq.com>
Date: Wed, 13 May 2026 11:24:46 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AD=A6=E7=94=9F=E4=BD=9C=E4=B8=9A=E8=AF=A6?=
 =?UTF-8?q?=E6=83=85?=
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---
 WeChatApplet/Services/Impl/HomeWorkService.cs | 55 ++++++++++---------
 1 file changed, 28 insertions(+), 27 deletions(-)

diff --git a/WeChatApplet/Services/Impl/HomeWorkService.cs b/WeChatApplet/Services/Impl/HomeWorkService.cs
index 91007fa..efb82ab 100644
--- a/WeChatApplet/Services/Impl/HomeWorkService.cs
+++ b/WeChatApplet/Services/Impl/HomeWorkService.cs
@@ -300,42 +300,43 @@ namespace YD_WeChatApplet.Api.Services.Impl
         /// 学生作业详情
         /// </summary>
         /// <param name="homeWorkId">作业Id</param>
+        /// <summary>
+        /// 学生作业详情
+        /// </summary>
         public async Task<StudentHomeWorkDetailDto> HomeWorkDetailsByStudent(int homeWorkId)
         {
-            // 获取当前登录学生学号
             var studentNo = UserLoginContext.Current.UserNo;
             if (string.IsNullOrEmpty(studentNo))
                 throw new Exception("未获取到当前学生信息");
 
-            // 联合作业表和学生作业关联表，筛选出指定作业且属于当前学生的记录
-            var query = from h in _sportsContext.HomeWork
-                        join hs in _sportsContext.HomeWorkStudents on h.Id equals hs.HomeWorkId
-                        where h.Id == homeWorkId && hs.StudentNo == studentNo
-                        select new { HomeWork = h, StudentWork = hs };
+            // 方案：直接投影到目标 DTO，并处理所有可能为 null 的数据库字段
+            var dto = await _sportsContext.HomeWork
+                .Where(h => h.Id == homeWorkId)
+                .SelectMany(h => h.HomeWorkStudents, (h, hs) => new { h, hs })  
+                .Where(x => x.hs.StudentNo == studentNo)
+                .Select(x => new StudentHomeWorkDetailDto
+                {
+                    Id = x.h.Id,
+                    WorkName = x.h.WorkName + "-" + x.h.WorkType.GetDescription(), 
+                    WorkText = x.h.WorkText,
+                    StartTime = x.h.StartTime,
+                    EndTime = x.h.EndTime,
+                    StudentScope = x.h.StudentScope == 1 ? "全部学生" : "部分学生",
+                    WorkModeType = x.h.WorkModeType,
 
-            var data = await query.FirstOrDefaultAsync();
-            if (data == null)
+                    StudentNo = x.hs.StudentNo,
+                    StudentName = x.hs.StudentName ?? "", 
+                    Sex = x.hs.Sex,         
+                    Photo = x.hs.Photo ?? "",
+                    WorkStatus = x.hs.WorkStatus,    
+                    Value = x.hs.Value                
+                })
+                .FirstOrDefaultAsync();
+
+            if (dto == null)
                 throw new Exception("作业不存在或当前学生无权查看该作业");
 
-            // 组装平铺Dto
-            var dto = new StudentHomeWorkDetailDto
-            {
-                Id = data.HomeWork.Id,
-                WorkName = $"{data.HomeWork.WorkName}-{data.HomeWork.WorkType.GetDescription()}",
-                WorkText = data.HomeWork.WorkText,
-                StartTime = data.HomeWork.StartTime,
-                EndTime = data.HomeWork.EndTime,
-                StudentScope = data.HomeWork.StudentScope == 1 ? "全部学生" : "部分学生",
-                WorkModeType = data.HomeWork.WorkModeType,
-                StudentNo = data.StudentWork.StudentNo,
-                StudentName = data.StudentWork.StudentName,
-                Sex = data.StudentWork.Sex,
-                Photo = data.StudentWork.Photo,
-                WorkStatus = data.StudentWork.WorkStatus,
-                Value = data.StudentWork.Value
-            };
-
-            // 根据模式类型格式化结果（与老师详情接口逻辑一致）
+            // 格式化结果（与老师接口逻辑一致）
             if (dto.WorkModeType == WorkModeType.TimerCount)
                 dto.Result = $"{dto.Value}个";
             else