sum values in datatable using linq based on conditions

Question

Hi I'm having a datatable like mentioned below. ID Percentage 1 50 1 30 2 0 2 100 Result: ID Percentage 1 80 2 100 Now I need to sum the percentage for each ID and the percentage for each ID should be 0 or 100 percentage. If any one of the ID in table doesn't have 0 or 100 I need to alert. Pls suggest me how I can do this in linq and I think its the best way.

Lawrence P · Answer

public class holder { public int ID { get; set; } public int Percentage { get; set; } } void Main() { List myHolderList = new List (){ new holder(){ ID=1 Percentage=50} new holder() { ID=1 Percentage=30} new holder() {ID=2 Percentage =0} new holder(){ID=2 Percentage =100}}; var result = myHolderList .GroupBy (hl =>new {myID =hl.ID }) .Select (hl =>new {hl.Key.myID Total =hl.Sum(h=>h.Percentage) }).ToList(); } // Define other methods and classes here List myID Total 1 80 2 100

pritaeas · Answer

Here's an example: class Custom { public int Id { get; set; } public int Percentage { get; set; } } void Main() { List data = new List () { new Custom() { Id = 1 Percentage = 50 } new Custom() { Id = 1 Percentage = 30 } new Custom() { Id = 2 Percentage = 0 } new Custom() { Id = 2 Percentage = 100 } }; IEnumerable summedData = data.GroupBy(item => item.Id).Select(grp => new Custom() { Id = grp.Key Percentage = grp.Sum(item => item.Percentage) }); foreach (Custom item in summedData) { Debug.WriteLine(string.Format(ID: {0} Percentage: {1} item.Id item.Percentage)); } Debug.WriteLine(); IEnumerable alertData = summedData.Where(item => item.Percentage > 0 && item.Percentage foreach (Custom item in alertData) { Debug.WriteLine(string.Format(ID: {0} Percentage: {1} item.Id item.Percentage)); } }