Deep null check inside linq expression, is there a better way?

Question

Unless it's in the Linq expression I could use the operator "?.". But since I can't use it in Linq, it's bad code writing. How can I do a deep null check?

_collection.Select(x=> new CollectionModel
{
Title = x.CollectionValues != null &&
        x.CollectionValues.Any(x => x.Amount == amount) &&
        x.CollectionValues.First(x => x.Amount == amount).TranslationTitle != null && 
        x.CollectionValues.First(x => x.Amount == amount).TranslationTitle.TranslationValues != null &&
        x.CollectionValues.First(x => x.Amount == amount).TranslationTitle.TranslationValues.Any(x => x.LanguageId == languageId) ?
        x.CollectionValues.First(x => x.Amount == amount).TranslationTitle.TranslationValues.FirstOrDefault(x => x.LanguageId == languageId).Value 
        : ""
}
)

Please add the LINQ provider that you are using, for example Linq-To-Entities — Tim Schmelter, Jan 13 '22 at 15:48

score 1 · Accepted Answer · answered Jan 13 '22 at 16:49

1

Try to do not do any null checks in LINQ to Entities query. EF should handle nulls automatically:

_collection.Select(x=> new CollectionModel
    {
        Title = x.CollectionValues!.FirstOrDefault(x => x.Amount == amount)!
            .TranslationTitle.TranslationValues!
            .FirstOrDefault(x => x.LanguageId == languageId)!
            .Value ?? ""
    }
);

answered Jan 13 '22 at 16:49

Svyatoslav Danyliv

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Thanks to you, I learned the null-forgiving operator. But here(https://stackoverflow.com/questions/54724304/what-does-null-statement-mean) "In some (edge) cases, the compiler is not able to detect that a nullable value is actually non-nullable." gives a warning like Is this usage a problem? – codinges Jan 13 '22 at 18:16

Deep null check inside linq expression, is there a better way?

1 Answers1