CODEWITHSUNDEEP
c#asp.netarrayssorting
Julius Doan
Julius Doan

Reputation: 356

Sorting a nested list array in C#

I am trying to sort a nested array of elements in asp.net and having a bit of trouble. Currently I have a playlist which has a model as so: 

public class Playlist
{
    public Playlist()
    {
        this.date = new List<dates>();
    }
    [Key]
    public int id { get; set; }
    public string UserId { get; set; }
    public List<dates> date { get; set; }

    public class dates
    {
        [Key]
        public int dates_id { get; set; }
        public List<places> place {get; set;}
    }

    public class places
    {
        [Key]
        public int places_id { get; set; }
        public string id { get; set; }
    }
}`

As you can see it is a nested array of objects, dates, with another array of objects, places.

What I am doing now is pulling out the data as so:

playlist = db.Playlists.Where(e => e.UserId.Equals(userId)).OrderBy(q => q.id).Include("date.place").ToList();

What I realized was that the places in the date object wasn't being pulled out in a sorted array based on the place_Id, but rather randomly. Is there a way that I could pull out the playlist with the places ordered? The .OrderBy(q => q.id) would only pull an ordered list for the playlist and not the nested objects.

Upvotes: 0

Views: 1552

Answers (2)

alexm
alexm

Reputation: 6882

You can arrange the order of items in nested lists on the client:

// Fetch playlists given a user id
var playlist = db.Playlists
      .Where(e => e.UserId.Equals(userId))
      .OrderBy(q => q.id)
      .Include("date.place")
      .ToList();

// Order places and dates by their id's
foreach(var item in playlist)
{
   foreach(var d in item.dates)
   {
        d.places.Sort((left, right) => 
         left.id.CompareTo(right.id));
   }

   item.dates.Sort((left, right)=>
      left.id.CompareTo(right.id));
}

Upvotes: 2

Avin Zarlez
Avin Zarlez

Reputation: 1682

First, you should sort each objects places lists, then sort the main/date list.

Attempting to sort both at once might cause random results

Upvotes: 0

Related Questions