CODEWITHSUNDEEP
c#linqnull
PoliDev
PoliDev

Reputation: 1458

Issue in check Null condition using linq query

I used joins and select query for passing dynamic values for the particular entity, Some fields are null in db. So i check the condition !=null condition but the whole select statement is throwing error if i use that field.

My code as follows, 

@placementId is as input value

IEnumerable<Submission> sub= from cc in confirmedCarrierRepository
    join cs in carrierSubmissionRepository on cc.ConfirmedCarrierID equals cs.ConfirmedCarrierID
    where cr.PlacementID == placementId
    //orderby c.panel is missed

    select new SubmissionEntity
    {
        PlacementId = placementId,
        //The ComissionId is null in db,
        CommissionId = cs.CommisionID.HasValue ? cs.CommisionID.ToString() : string.Empty
    }

Another way:

CommissionId= cs.CommisionID!=null ? cs.CommissionID : new int()

I can't understand why. Even i check null condition also how could the whole select won't work. Please help me to find out.

Upvotes: 2

Views: 4253

Answers (2)

Anonymous Duck
Anonymous Duck

Reputation: 2978

Use c# coalesce operator 

 CommissionId = (cs.CommisionID ?? 0).ToString();

Upvotes: 0

Rapha&#235;l Althaus
Rapha&#235;l Althaus

Reputation: 60493

If you're working in an IQueryable world (meaning your linq must generate a db query), then ToString() is not allowed.

You may use SqlFunctions.StringConvert

I'm not sure that HasValue is allowed either (you may just try), but != null is certainly allowed

Assuming CommissionId is an int? in your entity :

The "string" way

CommissionId = cs.ComissionId != null ? SqlFunctions.StringConvert((double)cs.CommmissionId) : string.Empty

The "int" way

CommissionId= cs.CommisionID ?? 0 // or default(int), but not new(int)

Upvotes: 1

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