Question

Hello everyone can anybody please help me to convert this sql to linq I thnink my biggest problem comes from the not exists statement in sql to linq

select count(distinct(GroupID)) from ParticipantModulequestionnaire pmq
inner join ParticipantGroupMember pgm on pmq.participantid = pgm.ParticipantID 
where pmq.moduleid = 46 and  not exists
(select unf.participantid from ParticipantModuleQuestionnaire unf where unf.ParticipantID = pmq.ParticipantID
and unf.ModuleID = 46
and isnull(unf.completedflag,0) <> 0)

Thank you all

Answer 1

You can just do a subquery and check that Any() is false. I think this should do it (there will be a couple of minor tweaks necessary to fit it to whatever your context is).

var query = 
        from p in ParticipantModulequestionnaire
        join g in ParticipantGroupMember on p.ParticipantId = g.PariticipamtnId
        where p.ModuleId == 46 
         && !ParticipantModuleQuestionnaire.Any(a => 
                        a.ParticipantId = p.ParticipantId
                        && a.ModuleId == 46
                        && (a.CompletedFlag ?? 0) != 0)
        select [p or g, I don't know which].GroupId;
var result = query.Distinct().Count();