How to use GroupBy using Dynamic LINQ

c#, dynamic-linq, linq

Solution

There is default `it` defined, you can use it to return matched elements:

var mydataGrouped = mydata.GroupBy("Shop", "it");

To iterate through results you should additionally `Select` elements to name it and use `dynamic`s:

var mydataGrouped = mydata.GroupBy("Shop", "it").Select("new (it.Key as Shop, it as Albums)");

foreach (dynamic group in mydataGrouped)
{
   foreach (dynamic album in group.Albums)
   {
      Console.WriteLine(album.Author);
   }
}

Problem

I am trying to do a GroupBy using Dynamic LINQ but have trouble getting it to work. This is some sample code illustrating the problem: ``` List<dtoMyAlbum> listAlbums = new List<dtoMyAlbum>(); for (int i = 0; i < 5000; i++) { dtoMyAlbum album = new dtoMyAlbum { Author = "My Author", BookID = i, CurrSymbol = "USD", Price = 23.23, Shop = i % 3 == 0 ? "TESCO" : "HMV" }; listAlbums.Add(album); } IQueryable<dtoMyAlbum> mydata = listAlbums.AsQueryable(); int count = mydata.Count(); //var mydataGrouped = mydata.GroupBy(a => a.Shop); // <-- this works well (but is not dynamic....) var mydataGrouped = mydata.GroupBy("Shop"); // <-- does not compile but is kind of what I want... foreach (var group in mydataGrouped) { //count = group.Count(); } ``` I realise that I am missing the 'elementSelector' in the GroupBy overload but all I want to do is to end up with (in this case) two sets of dtoMyAlbum objects so I wish to select ALL elements for all sets... How would I go about this?

Original source

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