Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
904 views
in Technique[技术] by (71.8m points)

entity framework - How to limit number of related data with Include

class Cat
{
   public int CatID;
   public string Name;
   public ICollection<Post> Posts;
}
class Post
{
   public int PostID;
   public string Name

   public int CatID;
   public virtual Cat Parent;
}

And I want to load all the Cat(egories) with their Posts so:

var cats = context.Cat.Include(c => c.Posts);

Now I want to limit the number of Posts that are returned, can someone show me how to do that?

I'm using EntityFramework 4.3.1

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

It is not possible with eager loading (Include) - eager loading returns always all related data. You must use projections to anonymous or new type (you cannot use your existing mapped entities):

var cats = context.Cat.Select(c => new 
{ 
    Category = c, 
    Posts = c.Posts.OrderBy(p => p.Name).Take(10) 
});

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...