Question

I have a list of items that can be represented like this:

ClientNo     Name     Date        Time
0001         Mike     01/12/2000    6
0002         Dave     01/12/2000   12
0001         Mike     01/12/2000   10
0002         Dave     02/12/2000    6

Is it possible to group and aggregate this to look something like this using LINQ?

ClientNo     Name     Date        Time
0001         Mike     01/12/2000  16
0002         Dave     01/12/2000  12
0002         Dave     02/12/2000   6

I am trying to return an aggregate row for each client for a particular date. I have been fiddling with the following but have not been able to get it right. Unfortunately my knowledge of LINQ is quite poor.

var result = from p in ListofModel
             group p by new { p.ClientNo, p.Date, p.Name, p.Time } into g
             orderby g.key.Date
             select new ModelClass
             {
                 ClientNo = g.Key.ClientNo,
                 Name = g.key.Name,
                 .....
             }

Not surprisingly this does not give me the results I would like. How can it be fixed?

Answer 1

I think it should look like this:

from p in ListofModel
group p by new { p.ClientNo, p.Date, p.Name } into g
orderby g.key.Date
select new ModelClass
{
    ClientNo = g.Key.ClientNo,
    Name = g.key.Name,
    Date = g.Key.Date,
    Time = g.Sum(x => x.Time)
}

You don’t want to group by the time, so it should not be included in the group key.