Question

I thought it’ll be easy but i’m really struggling with this.

I have a Table with this schema:
Name, Date, Value

Here’s what I’m trying to achive:

1. group all rows by ‘Name’
2. from that group, select the ‘Value’ which it’s ‘Date’ is the
   biggest

The #1 was easily achieved by GroupBy(“Name”,”it”)
but, now what…?
How do i query the grouped results???

Thank you all.

Answer 1

One of the assumptions I’ve made from your question is “Date is the biggest” you mean the latest one for each.

var data = new List<Data>
                             {
                                 new Data() {Name = "one3", Date = new DateTime(2001, 11, 11), Value = 7},
                                 new Data() {Name = "one2", Date = new DateTime(2001, 11, 11), Value = 111},
                                 new Data() {Name = "one2", Date = new DateTime(2011, 11, 11), Value = 7},
                             };

var result = data.GroupBy(x => x.Name).Select(grouping => grouping.OrderByDescending(x => x.Date).Take(1).FirstOrDefault()).ToList();

I’m sure there is probably a better way of doing the linq query but I hope this at least points you in the right direction 🙂