Linq内部左连接返回结果太多

Question

自从我上次使用内连接后，我已经有多年了，所以我有点生疏。 它有3个表

相册，AlbumsImages和用户

现在首先在我的仓库我内左加入专辑和AlbumsImages，事情是我唯一的冷杉封面说明，然后用id DESC要从albumsimages为了第一entery （在AlbumImages中可以有0张图片！）。在那之后，我是否会加入我的用户表，在相册中的用户ID上以用户身份登录。 我的问题是，我没有得到只有1张专辑，但每张图像在albumsImages，我只想要1的结果。 我在这里做错了什么？

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(); 

测试：

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

从albumImages起飞DefaultIfEmpty。无论是否存在匹配（左连接），这将返回专辑图像。