Using a partial class property inside LINQ statement

Question

I am trying to figure out the best way to do what I thought would be easy. I have a database model called Line that represents a line in an invoice.

It looks roughly

Answer 1

Try something like this:

var invoices =
    (from c in _repository.Customers
    where c.Id == id
    from i in c.Invoices
    select new 
    {
        Id = i.Id,
        CustomerName = i.Customer.Name,
        Attention = i.Attention,
        Lines = i.Lines,
        Posted = i.Created,
        Salesman = i.Salesman.Name
    })
    .ToArray()
    .Select (i =>  new InvoiceIndex
    {
        Id = i.Id,
        CustomerName = i.CustomerName,
        Attention = i.Attention,
        Total = i.Lines.Sum(l => l.Total),
        Posted = i.Posted,
        Salesman = i.Salesman
    });

Basically this queries the database for the records you need, brings them into memory and then does the summing once the data is there.