LINQ to SQL的一對多關係

Question

過去幾天我用LINQ querys表現掙扎：

LinqConnectionDataContext context = new LinqConnectionDataContext(); 
System.Data.Linq.DataLoadOptions options = new System.Data.Linq.DataLoadOptions(); 
options.LoadWith<Question>(x => x.Answers); 
options.LoadWith<Question>(x => x.QuestionVotes); 
options.LoadWith<Answer>(x => x.AnswerVotes); 
context.LoadOptions = options; 
var query =(from c in context.Questions 
      where c.UidUser == userGuid 
      && c.Answers.Any() == true 
      select new 
      { 
       c.Uid, 
       c.Content, 
       c.UidUser, 
       QuestionVote = from qv in c.QuestionVotes where qv.UidQuestion == c.Uid && qv.UidUser == userGuid select new {qv.UidQuestion, qv.UidUser }, 
       Answer = from d in c.Answers 
         where d.UidQuestion == c.Uid 
         select new 
         { 
          d.Uid, 
          d.UidUser, 
          d.Conetent, 
          AnswerVote = from av in d.AnswerVotes where av.UidAnswer == d.Uid && av.UidUser == userGuid select new { av.UidAnswer, av.UidUser } 
         } 
      }).ToList(); 

查詢必須通過5000行中運行，它需要長達1分鐘。我如何提高此查詢的性能？

更新：

Answer 1

讓你開始的東西。

CREATE PROCEDURE GetQuestionsAndAnswers 
(
    @UserGuid VARCHAR(100) 
) 
AS 
BEGIN 

SELECT 
c.Uid, 
c.Content, 
c.UidUser, 
qv.UidQuestion, 
qv.UidUser, 
av.UidAnswer, 
av.UidUser, 
av.Content, 
d.Uid, 
d.UidUser, 
d.Content 
FROM Question c 
INNER JOIN QuestionVotes qv ON qv.UidQuestion = c.Uid AND qv.UidUser = @UserGuid 
INNER JOIN Answers d ON d.UidQuestion = c.Uid 
INNER JOIN AnswerVotes av ON av.UidAnswer = d.Uid AND av.UidUser = @UserGuid 
WHERE c.UidUser = @UserGuid 

END 

您將已經聚集在默認情況下主列的索引（剛剛證實這一點在你的數據庫端），以及你希望非聚集索引上QuestionVote - UidUser柱，AnswerVote - UidUser列，答案 - UidQuestion列。

也看看這裏。你可能想使用.AsQueryable()而不是ToList()延期執行

Do you ToList()?

Answer 2

經過了使用sql-debug-visualizer，然後複製生成的SQL和SQL客戶端運行它，看看它是如何花費的時間生成的SQL。如果需要近1分鐘，你需要通過添加索引和/或存儲過程或創建視圖等

到imporve在數據庫級性能若以上沒有采取太多的時間，你可以隨時創建Stored Procedure and call that using LINQ to SQ L.

還有一個建議是使用實體框架if you can change to because這是未來。