linq-group

Please have a look at below example. The Group Clause has to be dynamic. Can you please guide me how this can be achieved. i.e. the row { r.Portfolio, r.DataType } has to be constructed dynamically. Not sure how I can tweak the solution as given at blog http://jonahacquah.blogspot.com/2012/02/groupby-multiple-columns-using-dynamic.html public class DecisionSupportData { public string Portfolio { get; set; } public string BucketName { get; set; } public string DataType { get; set; } public string ChildPortfolio { get; set; } } public void PopulateData() { List<DecisionSupportData> lstAllDecSupp

I have a list of items as such: public class Item { public int ItemId { get; set; } public string ItemName { get; set; } public int ListId { get; set; } } 1 Test1 1 2 Test2 1 3 Test3 1 4 List 2 5 List2 2 6 Testing 3 7 Testing2 3 8 Testing3 3 Is there a way for me to group by the ListId and put them into each separate buckets, i.e, ListId1 bucket will have all items with ListId == 1 . The list is dynamically returned from SQL, so I don't know before hand how many ListId there will be. You can use GroupBy : var groups = items.GroupBy(item => item.ListId); foreach(var group in groups) { Console

I have a very simple List<string> setup which contains lots of single characters per item (IE a foreach would console out to "a" "k" "p" etc) What I'd like to do is be able to group the items and also count how many of each occurs so I'd get an output similar to: a - 2 t - 3 y - 3 Any tips on the best way to do this? I am using .Net 4 if that's any help. (Given that each entry is a single character, is there any reason you don't have a List<char> by the way?) How about: // To get a Dictionary<string, int> var counts = list.GroupBy(x => x) .ToDictionary(g => g.Key, g => g.Count()); // To just

I'm looking for the LINQ equivalent to the Sybase's LIST() or MySQL's group_concat() It'll convert: User Hobby -------------- Bob Football Bob Golf Bob Tennis Sue Sleeping Sue Drinking To: User Hobby -------------- Bob Football, Golf, Tennis Sue Sleeping, Drinking That's the GroupBy operator. Are you using LINQ to Objects? Here's an example: using System; using System.Collections.Generic; using System.Linq; public class Test { static void Main() { var users = new[] { new { User="Bob", Hobby="Football" }, new { User="Bob", Hobby="Golf" }, new { User="Bob", Hobby="Tennis" }, new { User="Sue",