Linq: Sum int
I get " A null value cannot be assigned to a member of type System.Int32, which is a non-nullable value type " when I execute Sum () of my empty statement. ResultView works fine, but
var r = from v in DataContext.Visits
join bs in DataContext.BaseContents on v.BaseContentID equals bs.Id
where (bs.CreatedBy == userId) && (v.DateVisited.Year == workDate.Year) &&
(v.DateVisited.Month == workDate.Month) && (v.DateVisited.Day == workDate.Day) &&
(v.IsPreviewed == false) && (bs.ProfileProjectId != null)
select v;
int? number = r.Sum( v => v.Counter);
or
var r = from v in DataContext.Visits
join bs in DataContext.BaseContents on v.BaseContentID equals bs.Id
where (bs.CreatedBy == userId) && (v.DateVisited.Year == workDate.Year) &&
(v.DateVisited.Month == workDate.Month) && (v.DateVisited.Day == workDate.Day) &&
(v.IsPreviewed == false) && (bs.ProfileProjectId != null)
select v.Counter;
int? number = r.Sum(v);
doesn't work with the same exception.
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3 answers
Could you include some sample data? At least you can grab r.ToList () and look at the values manually. From what I can see it looks like it should work fine. Also make sure v.BaseContentID, bs.Id and v.DateVisited are not NULL. (especially id columns). Any referenced null integers can throw this exception. Not only those listed in the Select clause
var r = from v in DataContext.Visits
join bs in DataContext.BaseContents on v.BaseContentID equals bs.Id
where (bs.CreatedBy == userId)
&& (v.DateVisited.Date == workDate.Date)
&& (!v.IsPreviewed)
&& (bs.ProfileProjectId.HasValue)
select v;
int? number = r.Sum(v => v.Counter);
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