Linq內部左連接返回結果太多

Question

自從我上次使用內連接後，我已經有多年了，所以我有點生疏。 它有3個表

相冊，AlbumsImages和用戶

現在首先在我的倉庫我內左加入專輯和AlbumsImages，事情是我唯一的冷杉封面說明，然後用id DESC要從albumsimages爲了第一entery （在AlbumImages中可以有0張圖片！）。在那之後，我是否會加入我的用戶表，在相冊中的用戶ID上以用戶身份登錄。 我的問題是，我沒有得到只有1張專輯，但每張圖像在albumsImages，我只想要1的結果。 我在這裏做錯了什麼？

public IQueryable<Album> Get() 
    { 
     return (from a in context.Albums 
       join i in _imageRepository.Get() on a.Id equals i.AlbumId into albumImages 
       from cover in albumImages.DefaultIfEmpty() 
       orderby cover.Cover descending, cover.Id ascending 
       select new Album() 
        { 
         Id = a.Id, 
         UserId = a.UserId, 
         Name = a.Name, 
         Created = a.Created, 
         LastEdit = a.LastEdit, 
         Description = a.Description, 
         Views = a.Views, 
         Location = a.Location, 
         Photoshoot = a.Photoshoot, 
         Cover = cover, 
        }); 
    } 

var albums = (from a in AlbumRepository.Get() 
          join u in UserRepository.Get() on a.UserId equals u.Id 
          orderby a.Id descending 
          select new AlbumDisplayModel() 
           { 
            Album = a, 
            User = u 
           }).ToList(); 

測試：

return (from i in _imageRepository.Get() 
      join album in context.Albums on i.AlbumId equals album.Id into albums 
      from a in albums.DefaultIfEmpty() 
      select new Album() 
       { 
        Id = a.Id, 
        UserId = a.UserId, 
        Name = a.Name, 
        Created = a.Created, 
        LastEdit = a.LastEdit, 
        Description = a.Description, 
        Views = a.Views, 
        Location = a.Location, 
        Photoshoot = a.Photoshoot, 
        Cover = i, 
       }); 

Answer 1

從albumImages起飛DefaultIfEmpty。無論是否存在匹配（左連接），這將返回專輯圖像。