C# 实体框架查询#1

我正在试图找出如何限制我的子数据集只包含活动记录

    // Here's what I have currently...
    m_BackLoggerEntities.Stories
     .Include("Sprints")
     .Include("Tasks")
     .Include("Efforts")
     .Include("Products")
     .First(s => s.StoryId == id);


    // Here's what I thought I could do...
    m_BackLoggerEntities.Stories
     .Include("Sprints")
     .Include("Tasks")
     .Include("Efforts")
     .Include("Products")
     .Where(s => s.Tasks.Active)
     .First(s => s.StoryId == id);


    // I also tried this...
    m_BackLoggerEntities.Stories
     .Include("Sprints")
     .Include("Tasks")
     .Include("Efforts")
     .Include("Products")
     .First(s => s.StoryId == id && s => s.Tasks.Active));

---

显然，这些都不起作用。我不知道还能怎么做…

我发现“模拟”我想要的东西的唯一方法是使用

        var storyToDetail =
            m_BackLoggerEntities.Stories
                .Include("Sprints")
                .Include("Tasks")
            .Include("Efforts")
            .Include("Products")
                .First(s => s.StoryId == id);

然后在foreach的视图中

            <% foreach (var task in Model.Tasks.Where(t => t.Active))

t.Active）

但是这当然带来了比我想要的更多的记录。

看看。 根据链接文章中的示例，可以这样做：

var query = from story in m_BackLoggerEntities.Stories
            where story.StoryId == id
            select new {
                          story,
                          Tasks = from task in story.Tasks
                                  where task.Active
                                  select task
                       };

var stories = query
   .AsEnumerable()
   .Select(x => x.Story);

Model = m_BackLoggerEntities.Stories
    .Include("Sprints")
    .Include("Tasks")
    .Include("Efforts")
    .Include("Products")
    .SingleOrDefault(s => s.StoryId == id);

---

“故事”中的每个故事都应该只有活动任务。

您需要这样的内容：

var query = from story in m_BackLoggerEntities.Stories
            where story.StoryId == id
            select new {
                          story,
                          Tasks = from task in story.Tasks
                                  where task.Active
                                  select task
                       };

var stories = query
   .AsEnumerable()
   .Select(x => x.Story);

Model = m_BackLoggerEntities.Stories
    .Include("Sprints")
    .Include("Tasks")
    .Include("Efforts")
    .Include("Products")
    .SingleOrDefault(s => s.StoryId == id);

那么，在你看来：

@foreach (var task in Model.Tasks.Where(t => t.Active))

---

到底是什么问题？你有例外吗？零结果？结果太多了？？？这是一个非常古老的问题。。。。“09年10月29日”谢谢，但我尽量避免使用foreach。它是如何实施的对我来说无关紧要。