How to create linq query to join rows into string? - asp.net-mvc

Question

I have a table with the following fields:
Id Name Score Event
(1 John 2 3)
(2 John 4 3)
(3 john 5 3)
and I would like to get the following result:
(John, "2 +4+5", 11(Total score))
I'm trying to combine the results to show the sum in a string format then show the sum result.
Can anyone please help me with this issue.
Thank you,
Franciso

Answer 1

You need to call the toList() method before using methods like string.Format or string.Join because they are not supported by Linq to SQL.
You should modify your code into something like this:
var group = (from Classificacao in _dbSet.classificacao
from Evento in _dbSet.evento
where Classificacao.class_id_Evento == id_evento
where Evento.id_evento == id_evento
group Classificacao by new
{
Classificacao.class_atletaNome,
Classificacao.class_numAtleta,
Classificacao.class_atletaEquipa,
Classificacao.class_paisAtleta,
Evento.even_name,
Evento.local.local_nome,
Evento.compTipo.CompTipo_name
} into g).ToList()
The idea is to materialize the query into a list before calling the methods.
var model = group.Select(g => new
{
g.Key.class_numAtleta,
g.Key.class_atletaEquipa,
g.Key.class_atletaNome,
g.Key.class_paisAtleta,
class_fianlAtleta = g.Sum(c => c.class_fianlAtleta.Value),
class_classGeral = g.Min(c => c.class_fianlAtleta.Value),
class_nome = g.Key.even_name,
local_nome = g.Key.local_nome,
CompTipo_name = g.Key.CompTipo_name,
class_40ponto = ((from u in g
where u.class_id_Evento == id_evento
group u by new
{
u.class_atletaNome,
u.class_fianlAtleta
}
into k
select new
{
//Score = string.Concat(k.Key.class_fianlAtleta.ToString(), " + ", g.Key.class_atletaNome)
Score = string.Format("{0}",k.Key.class_fianlAtleta)
})).Select(c=>c.Score).FirstOrDefault()
}).OrderBy(c => c.class_fianlAtleta).ThenBy(c => c.class_classGeral)).toList();
I can't check if the code is correct therefore I leave it to you, anyway once you have your List in memory you can apply the methods supported by Linq to entity.

Answer 2

Here is my code:
var model = (from Classificacao in _dbSet.classificacao
from Evento in _dbSet.evento
where Classificacao.class_id_Evento == id_evento
where Evento.id_evento == id_evento
group Classificacao by new
{
Classificacao.class_atletaNome,
Classificacao.class_numAtleta,
Classificacao.class_atletaEquipa,
Classificacao.class_paisAtleta,
Evento.even_name,
Evento.local.local_nome,
Evento.compTipo.CompTipo_name
} into g
select new
{
g.Key.class_numAtleta,
g.Key.class_atletaEquipa,
g.Key.class_atletaNome,
g.Key.class_paisAtleta,
class_fianlAtleta = g.Sum(c => c.class_fianlAtleta.Value),
class_classGeral = g.Min(c => c.class_fianlAtleta.Value),
class_nome = g.Key.even_name,
local_nome = g.Key.local_nome,
CompTipo_name = g.Key.CompTipo_name,
class_40ponto = ((from u in g
where u.class_id_Evento == id_evento
group u by new
{
u.class_atletaNome,
u.class_fianlAtleta
}
into k
select new
{
//Score = string.Concat(k.Key.class_fianlAtleta.ToString(), " + ", g.Key.class_atletaNome)
Score = string.Format("{0}",k.Key.class_fianlAtleta)
})).Select(c=>c.Score).FirstOrDefault()
}).OrderBy(c => c.class_fianlAtleta).ThenBy(c => c.class_classGeral);de here

Answer 3

You need something like this:
var result = table
.GroupBy(t => new { t.Name, t.Event })
.ToList()
.Select(t => new
{
Name = t.Key.Name,
JoinedScores = string.Join(" + ", t.Select(group => group.Score).ToArray()),
TotalScore = t.Sum(group => group.Score).ToString() + " (Total Score)"
}).ToList();
The first call to the ToList() method is needed because Linq to SQL will not support the calls to string.Join(). I'm not sure but probably you can replace it with a call to AsEnumerable().