I am trying to compute a sum of nullable int using Linq. My query looks like this:
int? surveysPromotersFromChatsGroup = (from surveyResult in surveyResultsFromChats
where surveyResult.FirstScoreNPS.HasValue && surveyResult.GroupID == gr && surveyResult.FirstScoreNPS >= 9
select surveyResult.FirstScoreNPS).Sum();
FirstScoreNPs field is a nullable int. My problem is that the sum always return null no matter what. I can't see the logic behind this. I checked and I know for certain that some entities do have values in that field and the sum method should sum up those values.
Another approach that I tried is like this:
int surveysPromotersFromChatsGroup = (from surveyResult in surveyResultsFromChats
where surveyResult.FirstScoreNPS.HasValue && surveyResult.GroupID == gr && surveyResult.FirstScoreNPS >= 9
select surveyResult.FirstScoreNPS).Sum(score => score.Value);
But I get an exception "linq the null value cannot be assigned to a member with type".
Isn't there a way to sum up the non null values from that field using linq?
The surveyResultsFromChat is actually from another query:
var surveyResultsFromChats = from surveyResult in db.SurveyResults
join survey in db.Surveys on surveyResult.SurveyID equals survey.SurveyID
join userGroup in db.UserGroupMaps on surveyResult.UserID equals userGroup.UserID
where surveyResult.CreatedDate >= startDate && surveyResult.CreatedDate <= endDate && surveyResult.UserID.HasValue && surveyResult.ChatSessionID.HasValue
select new { surveyResult.ResultID, survey.BrandID, userGroup.GroupID, surveyResult.CompletedDate, surveyResult.FirstScoreNPS };
FirstScoreNPS in my model is an Nullable int.
you can try out
(from surveyResult in
surveyResultsFromChats
where surveyResult.FirstScoreNPS.HasValue && surveyResult.GroupID == gr &&
surveyResult.FirstScoreNPS >= 9
select surveyResult.FirstScoreNPS).
Select(score => score.Value ?? 0).Sum();
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