Get tuple and list linked as result - linq

Question

I have this query :
var query = (from tables ...
where ...
select new
{
ClientName = ClientName,
ClientNumber = ClientNumber,
ClientProduct = ClientProduct
}).Distinct();
which returns rows with 3 values.
ClientName and ClientNumber can be linked to multiple products.
So we can have :
NameA NumberA Product1
NameA NumberA Product2
NameA NumberA Product3
NameB NumberB Product4
NameC NumberC Product5
I would like to know if it is possible to store that in a List of a certain class which would be like :
class MyClass
{
string ClientName,
int ClientNumber,
List<int> ClientProducts
}
So there are no duplicate of ClientName and ClientNumber.
Thank you in advance.

Answer 1

With this class structure to represent your data:
class MyClass
{
public string ClientName { get; set; }
public int ClientNumber { get; set; }
public List<int> ClientProducts { get; set; }
}
class Procuct
{
public string ClientName { get; set; }
public int ClientNumber { get; set; }
public int ProductID { get; set; }
}
and this test data:
List<Procuct> Products = new List<Procuct>()
{
new Procuct() { ClientName = "A", ClientNumber = 1, ProductID = 1},
new Procuct() { ClientName = "A", ClientNumber = 1, ProductID = 2},
new Procuct() { ClientName = "A", ClientNumber = 1, ProductID = 3},
new Procuct() { ClientName = "B", ClientNumber = 2, ProductID = 4},
new Procuct() { ClientName = "C", ClientNumber = 2, ProductID = 5}
};
you can use the following linq query:
var q = from p in Products
group p by new
{
cName = p.ClientName,
cNumber = p.ClientNumber
} into pGroup
select new MyClass
{
ClientName = pGroup.Key.cName,
ClientNumber = pGroup.Key.cNumber,
ClientProducts = pGroup.Select(x => x.ProductID).ToList()
};
to get exactly what you want, i.e. a collection of MyClass objects.
The Grouping performed in the above linq query essentially guarantees that there will be no duplicates on (ClientName, ClientNumber).

Answer 2

Since you mention Linq-to-sql, most probably you Client entity already has the products linked. You might look for an overcomplicated solution.
It depends a bit on your foreign key stucture, but if your datamodel would be
Client has 1-many product and you have a Foreign key from product to client it is already present.
So you can just reference client.Products.
So in your case it would be
var query = (from Clients...
where ...
select new
{
ClientName = Client.ClientName,
ClientNumber = Client.ClientNumber,
ClientProduct = Client.Products.Select(s=>s.id).ToList()
});
But you might as well simply use your client entity with a eager load of the products.
It all depends on your datamodel + proper foreign key structure
if you have a many-many associations like Product-per-client between your client and product you can start from that entity. Have a look at this documentation - it provides a good starting point for Linq-2-sql.
http://weblogs.asp.net/scottgu/using-linq-to-sql-part-1

Answer 3

I solve same problem , I think it useful to you
Only check your Where Condition properly
Thank...
var query = (from tables ...
where ...
select new
{
ClientName = ClientName,
ClientNumber = ClientNumber,
ClientProduct = ClientProduct.ToList()
}).Distinct();