LINQ-实体查询功能出错 [英] Error in linq-entity query function

问题描述

1.  public BoardPost GetPostByID(Int64 PostID)
    {
2.           BoardPost result = null;
3.           using(FisharooDataContext dc = _conn.GetContext())
            {
4.               BoardPost post = dc.BoardPosts.Include("Account").Where(p =>  
                     p.PostID == PostID).FirstOrDefault();
5.               result = post;
6.               result.Account = post.Account;
            }
7.           return result;
    }

我在第6行出现错误，可能是由于第4行的编码错误或缺少了一些参考.请帮帮我.谢谢亲爱的朋友.

[edit]添加了pre标签，并且未选中将我的内容作为纯文本而不是HTML对待 [/edit]

I get error at line no 6 probably due to wrong coding at line no 4 or due to some missing references. Please help me out. Thank you dear friends.

[edit]Added pre tag and unchecked Treat my content as plain text, not as HTML[/edit]

推荐答案

您的BoardPost post = dc.BoardPosts...行返回null，因此您的result.Account = post.Account失败，发布为null.

每当您执行一些操作以取回对象时，请始终确保该对象存在，然后再尝试使用它.

It is clear that your BoardPost post = dc.BoardPosts... line is returning null so your result.Account = post.Account is failing with post being null.

Whenever you do something to get an object back, always ensure that the object exists before trying to use it.

if( post != null )
   result.Account = post.Account;

至于linq的语法，我没有发现任何错误.

As to the syntax of the linq, I don''t see anything wrong with it off the top of my head.

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