Linq distinct - Count

Question

I am looking to perform a query on an example list of objects

Date     Username

01/01/2011 james
01/01/2011 jamie
01/01/2011 alex
01/01/2011 james
02/01/201         


        

Answer 1

I realize this is an ancient question but I ran across it and saw the comment about wanting method syntax and couldn't help myself to answer it... I may have a coding disorder.

In query syntax it looks like this... note that there is no query syntax for Distinct and Count

from l in logins
group l by l.Date into g
select new
{
    Date = g.Key,
    Count = (from l in g select l.Login).Distinct().Count() 
};

For a side by side comparison to the original method syntax (which personally I like better) here you go...

logins
  .GroupBy(l => l.Date)
  .Select(g => new
  {
    Date = g.Key,
    Count = g.Select(l => l.Login).Distinct().Count()
  });