CODEWITHSUNDEEP
c#linq
Volkan
Volkan

Reputation: 49

Linq where clause 2 condition order?

i tried this linq code for get questions

return (from i in db.Question 
        where i.Id == questionId || (i.RelatedId == questionId && i.IsAccept == isAccept)
        select i)
    .ToList();

I got 2 question but their order was wrong. Can I say to Linq get first where clause then second condition?

Note: First get i.Id == questionId then get second condition rows

Note2: Id and RelatedId is Guid. I am trying to do this without order by and single query

Upvotes: 0

Views: 190

Answers (3)

Volkan
Volkan

Reputation: 49

i tried this and looking work

List<Question> final = new List<Question>();
var result = (from i in db.Question where i.Id == questionId || (i.RelatedId == questionId && i.IsAccept == isAccept) select i).ToList();
final.Add(result.Where(a => a.Id == questionId).SingleOrDefault());
final.Add(result.Where(a => a.Id != questionId).SingleOrDefault());

im getting all with single query and adding them to list with conditions

Upvotes: 0

Fabio
Fabio

Reputation: 32455

For database queries you can use asynchronous queries and combine result later, which makes code little bid more comprehensible and asynchronous queries will be executed almost simultaneously.

var byIdTask = 
    db.Question.Where(question => question.Id == questionId).ToListAsync();
var relatedTask = 
    db.Question.Where(question => question.RelatedId = questionId)
               .Where(question => question.IsAccept == isAccept)
               .ToListAsync();

await Task.WhenAll(new[] byIdTask, relatedTask);

var allQuestions = byIdTask.Result.Concat(relatedTask.Result).ToList();

Upvotes: 0

Mahsa Aghajani
Mahsa Aghajani

Reputation: 127

You can keep a variable which shows the returned row, satisfies which of your conditions. Then select the row together with this variable(here named as 'order') in an anonymous type. Finally, OrderBy your results based on your variable and Select your row.

return (from i in db.Question
        where i.Id == questionId || (i.RelatedId == questionId && i.IsAccept == isAccept)
        let order = i.Id == questionId ? 1 : 0
        select new {i, order}).Orderby(a => a.order).Select(a => a.i)
    .ToList();

Upvotes: 2

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