Lambda表达式,其中ID在id列表中

Question

我有2个清单

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>();

我怎样才能得到答案,其中questionId为listquestionold: listanswers =db.tblanswers.where(p=> p.ExamQuestionId exists in listquestionold？

Answer 1

使用以下Contains方法很容易List:

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