Question

It seems like most LINQ is written with lambda expressions. How do I go about rewriting this linq using lambda, kinda confusion with the style (especially with joins)?

var responses =
            from c in questionRepository.GetReponses()
            join o in questionRepository.GetQuestions() on
            c.QuestionID equals o.QuestionID
            where c.UserID == 9999
            orderby o.DisplayOrder
       select new { o.QuestionText, c.AnswerValue };

Answer 1

I prefer the “LINQ syntax” for Joins as I think it looks cleaner.

In any case, here is how to translate the LINQ-join to the “Lambda Expression”-join.

The translation for:

from a in AA
join b in BB on
a.Y equals b.Y
select new {a, b}

Is:

AA.Join(                 // L
  BB,                    // R
  a => a.Y, b => b.Y,    // L -> join value, R -> join value
  (a, b) => new {a, b})  // L+R result

The other LINQ keywords are much simpler to convert (e.g. OrderBy(u => u.DisplayOrder) and are just “chained together” with .. – give it a go!