Question

以下查询在执行时无法加载表：

IEnumerable<Bookmark> tempBookmarks = ListBookmarksByUserID(userID);
IEnumerable<CandidateWithBookmarks> results = (from c in _internshipEntities.CandidateSet
                                            .Include("education")
                                            .Include("progress")
                                            .Include("contacts")
                                            .Include("availability")
                                            .Include("hosttypes")
                                            .Include("hostsizes")
                                            .Include("hostcapacities")
                                            .Include("hoststates")
                                            .Include("users")
                       join b in tempBookmarks on c.ID equals b.candidates.ID
                       select new CandidateWithBookmarks()
                                  {CandidateObject = c, BookmarkObject = b});
return results;

我找到了一些与此问题相关的文章，即Alex James' article "How to make Include really Include"。解决方案有一点需要注意：

为此，您的最终选择必须是实体，即选择帖子而不是选择新的{...}

这显然是上述代码块的问题。是否有任何其他已知的解决此问题的解决方案不会破坏急切的加载？

Answer 1

我认为我解决了这个问题，但它可能仅适用于此特定实例，通过在连接后移动包含，查询似乎有效：

IEnumerable<CandidateWithBookmarks> results = (
    from b in tempBookmarks
    join c in _internshipEntities.CandidateSet
                                 .Include("education")
                                 .Include("progress")
                                 .Include("contacts")
                                 .Include("availability")
                                 .Include("hosttypes")
                                 .Include("hostsizes")
                                 .Include("hostcapacities")
                                 .Include("hoststates")
                                 .Include("users")
    on b.candidates.ID equals c.ID
    select new CandidateWithBookmarks(){CandidateObject = c, BookmarkObject = b});

编辑：我有类似的另一个查询也需要一个外部联接，这会产生一些问题，因为它会影响你加入什么，不像这个例子，但它仍然可行。

在复杂查询中，实体框架中的急切加载失败

1 个答案: