EF查询，从发布内容的朋友处获得用户名

我正在构建类似于facebook的webapp。我想查询数据库，所以我得到当前的朋友登录用户的职位（从Facebook类似“家”）确定这里是EF查询，从发布内容的朋友处获得用户名

public User() 
    { 
     this.Friends = new HashSet<Friend>(); 
     this.Friends1 = new HashSet<Friend>(); 
     this.Posts = new HashSet<Post>(); 
    } 

    public int userID { get; set; } 
    public System.Guid user_Unique_ID { get; set; } 
    public string username { get; set; } 
    public string profilePicUrl { get; set; } 

    public virtual ICollection<Friend> Friends { get; set; } 
    public virtual ICollection<Friend> Friends1 { get; set; } 
    public virtual ICollection<Post> Posts { get; set; } 


public partial class Friend 
{ 
    public int friendshipID { get; set; } 
    public int userfrID { get; set; } 
    public int friendID { get; set; } 

    public virtual User User { get; set; } 
    public virtual User User1 { get; set; } 
} 

public partial class Post 
{ 
    public int postID { get; set; } 
    public int userpostID { get; set; } 
    public System.DateTime postedOn { get; set; } 
    public string text { get; set; } 
    public int likes { get; set; } 

    public virtual User User { get; set; } 
}

我被试车型，开创了视图模型：

public class HomePosts 
{ 
    public int postID { get; set; } 
    public int userID { get; set; } 
    public int userpostID { get; set; } 
    public string username { get; set; } 
    public string text { get; set; } 
    public System.DateTime postedOn { get; set; } 
    public int likes { get; set; } 
    public int userfrID { get; set; } 
    public int friendID { get; set; } 
}

，这里是我的查询：

using (var context = new ASPNETDBEntities()) 
     { 
      MembershipUser x = Membership.GetUser(); 
      User wad = context.Users.Where(u => u.user_Unique_ID == (System.Guid)x.ProviderUserKey).SingleOrDefault(); 
      int id = wad.userID; 
      var allposts = (from u in db.Users 
          join f in db.Friends 
          on u.userID equals f.userfrID 
          where f.userfrID == id 
          join p in db.Posts 
          on f.friendID equals p.userpostID 
          select new HomePosts 
          { 
           friendID = f.friendID, 
           likes = p.likes, 
           postedOn = p.postedOn, 
           postID = p.postID, 
           text = p.text, 
           userfrID = f.userfrID, 
           userID = u.userID, 
           username = u.username, <-- this is the problem 
           userpostID = p.userpostID 
          }).OrderByDescending(u => u.postedOn).ToList(); 
      return View(allposts); 
     }

的问题是，对于每一个岗位则显示当前登录用户的用户名，不从F用户名发布该帖子的朋友。我需要海报的用户名（朋友）。有什么建议吗？

来源

2012-06-15 Milanix

好吧，你可以试试这个：

from f in db.Friends 
join u in db.Users 
on f.friendID equals u.userID 
where f.userfrId = id 
join p in db.Posts        
on f.friendID equals p.userpostID        
select new HomePosts 
{         
    friendID = f.friendID,         
    likes = p.likes,         
    postedOn = p.postedOn,         
    postID = p.postID,         
    text = p.text,         
    userfrID = f.userfrID,         
    userID = u.userID,         
    username = u.username, 
    userpostID = p.userpostID        
}

或者，如果您的EF是否设置正确，你可以这样做：

var posts = db.Posts.Where(p => p.User.Any(u => u.Friends.Any(f => f.userfrID == id))).Select(p => new HomePosts 
    {         
     // your selections       
    } 

)

来源

2012-06-15 02:28:46 fenix2222

Ty只是帖子，第一个是答案 – Milanix

很高兴我可以帮助 – fenix2222

不应该在该部分

join p in db.Posts  
on f.friendID equals p.userpostID

是：

join p in db.Posts 
on u.userID equals p.userpostID

？

除非我misenterpreting，这听起来像你有什么说：

加入关于这篇文章的用户ID的职位表 - >当前用户 - >朋友 - >朋友id（其循环回来当前用户）

来源

2012-06-15 02:02:06 Terry

娜，与此，它显示从当前用户 – Milanix

EF查询，从发布内容的朋友处获得用户名

回答

相关问题