Linq: Find Element in a Collection

I have a collection called Albums with objects from the class Album. This class has a property Songs, which is a collection of Song objects. Each Song has an unique Id.

public IQueryable<Album> Albums

public class Album
{
    ...
    public virtual ICollection<Song> Songs { get; set; }
    ...
}

public class Song
{
    public int Id { get; set; }
    ...
}

Is it possible, using Linq, to find a Song in the Album collection? I have no idea how, I am new to Ling.
I tried a bit:

Albums.FirstOrDefault(a => a.Songs.Id == id);

Thanks a lot,

Vincent

Answers:

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Method 1

Albums.SelectMany(a=>a.Songs).FirstOrDefault(song => song.Id == id)

The SelectMany will create a flattened list of all songs for all albums allowing you to then select the first with the appropriate id.

Method 2

If you want to return the album that contains the song with a given Id, you should use the following query:

Albums.FirsOrDefault(a => a.Songs.Any(s => s.Id == Id));

if you want to get the song:

Albums.SelectMany(a=>a.Songs).FirstOrDefault(s => s.Id == Id);

Method 3

You need to do this if you have an album…

var album = GetAlbum();
var song = album.Songs.FirstOrDefault(s => s.ID == id);

Or this if you don’t…

var song = albumsCollection.SelectMany(s => s.Songs).FirstOrDefault(s => s.ID == id);

Method 4

My suggestion to find an ablum with a certain song:

Album albumFound = Albums.FirstOrDefault(item => item.Songs.FirstOrDefault(song => song.Id == id) != null);

Method 5

var query = from album in Albums
            from song in album.Songs
            where song.Id == id;

var song = query.FirstOrDefault();

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