自然連接在.NET

我試着做一個自然的左Linq中加入從2個表自然連接在.NET

2個表

| questions | 
+-----------+ 
| id  | 
| question | 
+-----------+ 


| answers | 
+-----------+ 
| id  | 
| q_id (fk)| 
| answer | 
+-----------+

我試着檢索單個行對於每一個問題，但與作爲可附加的cols需要

林不知道這是否可能

     ID | Question | Answer 1 | Answer 2 | An.... 
| view  |  |-----------------------------------------------+ 
+-----------+  | 1 | question | answer1 | answer2 | ... | 
| id  |  | 2 | question | answer1 | answer2 | ... | 
| question |  | 3 | question | answer1 | answer2 | ... | 
| answer1 | or | 4 | question | answer1 | answer2 | ... | 
| answer2 |  | 5 | question | answer1 | answer2 | ... | 
| answer3 |  | 6 | question | answer1 | answer2 | ... | 
| answer... |  | 7 | question | answer1 | answer2 | ... | 
+-----------+  |-----------------------------------------------+

我的C＃Linq

 var joinedTable = 
     from questions in db.Results 
     join answers in db.Answers on questions.id equals answers.result_id 
      into answers 
     select new 
     { 
      questions.id, 
      TOTAL_ANSWERS = answers.Count(), 
      questions.SurveyDateCreated, 
      (answers.ForEach(a=> a.answer) as "Answer" + i++) 
     };

來源

2012-11-15 user1827093

肯定無法實現的加入... –

[使用LINQ的Pivot數據]的可能重複（http://stackoverflow.com/questions/963491/pivot-data-using-linq） –

你在找什麼叫做PIVOT。最好的方法是在SQL中創建一個存儲過程，並在SQL中執行PIVOT。使用LINQ可能但很複雜。

透視使用LINQ： http://madhukap.blogspot.com/2011/05/pivot-with-linq.html http://stackoverflow.com/questions/167304/is-it-possible-to-pivot-data-using-linq

來源

2012-11-15 19:07:01 Sev

自然連接在.NET

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