Agfdhyk

I am reading a csv file.

The data is not sorted in any order. I have read the file using the below code

List<LatencyData> latencys = new List<LatencyData>();

        using (var reader = new StreamReader(filePath))

        {



            LatencyData latencyData = null;

            while (!reader.EndOfStream)

            {

                var line = reader.ReadLine();

                var values = line.Split(';');

                var row = values[0].Split(',');





                latencyData = new LatencyData

                {

                    TimeStamp = (row[0] + "000"),

                    Prefix = row[1],

                    Uplink = row[2],

                    Latency = row[3]

                };



                latencys.Add(latencyData);

            }

        }

The Next step was to group on the basis of Time stamp.

var grouped = latencys.GroupBy(item => item.TimeStamp);

which looks like this after grouping.

Now I want to transform the data into this format

timeStamp  Latency0 Latency1 Latency2 Latency3 Latency4

1541030400  198      267.67   263      null      198

for that i used this part.

var transformed = grouped.Select(g => new

        {

            Hubs = g.Select(hub => new

            {

                stamp = g.Key,

                Latency0 = g.Where(item => item.Uplink == "0").Select(data => data.Latency),

                Latency1 = g.Where(item => item.Uplink == "1").Select(data => data.Latency),

                Latency2 = g.Where(item => item.Uplink == "2").Select(data => data.Latency),

                Latency3 = g.Where(item => item.Uplink == "3").Select(data => data.Latency),

                Latency4 = g.Where(item => item.Uplink == "4").Select(data => data.Latency),

            })

        }); 

The Result is not correct and there is many rows for the same values are returned. It should have only one row per key

timeStamp  Latency0 Latency1 Latency2 Latency3 Latency4

1541030400  198      267.67   263      null      198

What am I doing wrong here?

You're almost there. However you might want to return a value for each latency instead of list of objects:

var transformed = grouped.Select(g => new

{

    Hubs = g.Select(hub => new

    {

       stamp = g.Key,

       Latency0 = g.FirstOrDefault(item => item.Uplink == "0")?.Latency,

       Latency1 = g.FirstOrDefault(item => item.Uplink == "1")?.Latency,

       Latency2 = g.FirstOrDefault(item => item.Uplink == "2")?.Latency,

       Latency3 = g.FirstOrDefault(item => item.Uplink == "3")?.Latency,

       Latency4 = g.FirstOrDefault(item => item.Uplink == "4")?.Latency,

    })

});