Linq - Data Entities - Records by Max Date with CASE

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 I needed to get essentially a summary by case statement for a given date.  As you can see I have defined the MAX date into a variable.  This example also shows using a substring of the first character in a LET statement
 DateTime? maxDate =
                (from a in context.tbl_tslog
                orderby a.CurrentTime
                select (DateTime?) a.CurrentTime ).Max();

 var dbRecords = (from c in context.tbl_testlog
                           where (c.CurrentTime >=maxDate)
                              
         let range = (  c.Usr.ToUpper().Substring(0,1) == "B" ? "US" :
                            c.Usr.ToUpper().Substring(0, 1) == "G" ? "CA" :
                            c.Usr.ToUpper().Substring(0, 1) == "U" ? "UK" : "Other"
                                              )
                                 group c by range into g
 select new { Group = g.Key, Users = g.Count(), Latest = g.Max(c => c.CurrentTime) }).ToList();

 The results bound to a grid look like this - 

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