LINQ .SUM() and nullable db values
What about excluding the nulls, ie
var expense =
from e in db.I_ITEM
where (e.ExpenseId == expenseId) && (e.Mileage.HasValue)
select e;
return expense.Sum(x => x.Mileage);
I'm surprised that fails, but an alternative which might work is simply to sum the nullable values and then use the null coalescing operator:
return expense.Sum(x => x.Mileage) ?? 0d;
Certainly in LINQ to Objects this would do the right thing, ignoring null values and giving you a null result (before the null coalescing operator) if there were no non-null values in the sequence.
may give you an opinion...
decimal depts = 0;
var query = from p in dc.Payments
where p.UserID == UserID
select p.Amount;
if (query.Count() > 0)
{
depts = query.Sum();
}
return depts;