LINQ Grouping or Splitting - linq

Question

Im having an issue doing something thats probably pretty simple.
My LINQ query is returning a result set of 10 objects.
Something like:
Name: Bill, Action: aaa, Id: 832758
Name: Tony, Action: aaa, Id: 82fd58
Name: Bill, Action: bbb, Id: 532758
Name: Tony, Action: bbb, Id: 42fd58
What I need to do, is to group these so that there are only 2 rows, ie one per Name, but have the ones with "Action: bbb" move into a different column. So the output would be:
Name: Bill, Action: aaa, Action_2: bbb, Id: 832758, Id_2: 532758
Name: Tony, Action: aaa, Action_2: bbb, Id: 82fd58, Id_2: 42fd58
Can anyone explain to me how I might do that?
Cheers

Answer 1

var myData = new []
{
new { Name = "Bill", Action="aaa", Id = "832758" },
new { Name = "Tony", Action="aaa", Id = "82fd58" },
new { Name = "Bill", Action="bbb", Id = "532758" },
new { Name = "Tony", Action="bbb", Id = "42fd58" }
};
var result = myData
.GroupBy(x=>x.Name)
.Select(g=>new
{
Name = g.Key,
Action = g.First().Action,
Action_2 = g.Last().Action,
Id = g.First().Id,
Id_2 = g.Last().Id
});
The query above assumes that you have only two rows for each name; if you have multiple rows per name, you can take the second Action/Id value by using .Skip(1).Take(1) instead of .Last()

Answer 2

I don't think there's a real simple way to do it. I've connocted this, though, which might get you started:
var myData = new []
{
new { Name = "Bill", Action="aaa", Id = "832758" },
new { Name = "Tony", Action="aaa", Id = "82fd58" },
new { Name = "Bill", Action="bbb", Id = "532758" },
new { Name = "Tony", Action="bbb", Id = "42fd58" }
};
// group all the Names together
var result = from m in myData
group m by m.Name into names
orderby names.Key
select names;
// go through each Name group and create the output string to store in sbLines
var sbLines = new StringBuilder();
foreach (var name in result)
{
var sb = new StringBuilder();
sb.AppendFormat("Name: {0}, ", name.Key);
int count = 1;
foreach (var item in name)
{
if(count > 1)
sb.AppendFormat("Action_{0}: {1}, ", count, item.Action);
else
sb.AppendFormat("Action: {0}, ", item.Action);
count++;
}
count = 1;
foreach (var item in name)
{
if(count > 1)
sb.AppendFormat("Id_{0}: {1}, ", count, item.Id);
else
sb.AppendFormat("Id: {0}, ", item.Id);
count++;
}
sbLines.Append(sb.ToString().Trim(new char[] { ' ',',' }));
sbLines.Append(Environment.NewLine);
}
Console.WriteLine(sbLines.ToString());
Run it here: http://ideone.com/8UTxr