How to select each splited string and group by with another members in linq?

Question

How to select many split string and group by with another members in linq?

class LogData
{
  public string IndexPattern {get; set;}
  public string Version {get;set;}
  public string Type1 {get; set;}
  public string Type2 {get; set;}

  //here has a constructor of this class
}

I have a list of Log Data Which have a many log datum. The index pattern is the set of log index which use the delimiter ",".

List<LogData> logList = new List<LogData>();
logList.add(new LogData("1,2,4", "Ver1", "pro" , "etc" ) );
logList.add(new LogData("1", "Ver2", "pro" , "etc" ) );
logList.add(new LogData("2", "Ver1", "pro" , "etc" ) );
logList.add(new LogData("1,2,4", "Ver1", "pro" , "etc" ) );
logList.add(new LogData("1,5", "Ver2", "pro" , "set" ) );

And i want split index patterns and group by all member like this.

[Index] [Version] [Type1] [Type2] [Count]
  1        Ver1     pro      etc    2
  2        Ver1     pro      etc    2
  4        Ver2     pro      etc    2
  1        Ver2     pro      etc    1
  1        Ver2     pro      set    1
  5        Ver2     pro      set    1
  4        Ver2     pro      set    1

And i write linq like this to group by first..

var LogGroup = HackingLogs.GroupBy(g => new {
              IndexPattern = g.IndexPattern.SelectMany( new { Index = c => c 
               }),  //I must select many to get each splited  string
                g.Version,
                g.Type1,
                g.Type2
 }); //I group by this for each splited string and all member pairs to select 

But it can not group by. so i can not use select. May i have some answer for this problem?

Answer 1

You can first flatten the IndexPattern using SelectMany and project all other elements. Finally group by all columns and get the Count. This should give you the expected output:-

 var res = logList.SelectMany(x => x.IndexPattern.Split(',')
                                  .Select(z => new 
                                      { 
                                           Index = z, 
                                           Version = x.Version, 
                                           Type1 = x.Type1, 
                                           Type2 = x.Type2 
                                      }))
                   .GroupBy(x => new { x.Index, x.Version, x.Type1, x.Type2 })
                   .Select(x => new
                        {
                            Index = x.Key.Index,
                            Version = x.Key.Version,
                            Type1 = x.Key.Type1,
                            Type2 = x.Key.Type2,
                            Count = x.Count()
                        });

Working Fiddle.