Lambda表达式，其中ID在id列表中

Question

我有2个列表

var listquestionold = db.tblExamQuetions.Where(p => p.QuetionExamId == oldexamid).ToList();
var listquestionnew = listquestionnew = db.tblExamQuetions.Where(p => p.QuetionExamId == examid ).ToList();
List<tblExamQuestionAnswers> listanswers = new List<tblExamQuestionAnswers>();

如何在questionId listquestionold中获得答案： listanswers =db.tblanswers.where(p=> p.ExamQuestionId exists in listquestionold？

Answer 1

使用List的<{3}}方法很容易：

var listquestionold = db.tblExamQuetions.Where(p => p.QuetionExamId == oldexamid).ToList();
var listanswers = db.tblanswers.Where(w => listquestionold.Contains(w.ExamQuestionId)).ToList();