使用LINQ模仿SQL IN子句

Question

我试图模仿SQL中常用的IN（）子句，并在我的LINQ语句中使用它。 我看到Contains（）有一个带有IEnumerable集合的重载。我试过传入ILIST和Dictionary，但两者都不正确。 我该如何做到这一点？

谢谢，非常感谢。

SQL

select 
oec.OnlineEducationCourseId, 
oec.CourseTitle,COUNT(oec.CourseTitle) as CourseCount
from OnlineEducationRegistration as oer
join OnlineEducationCourse oec on oec.OnlineEducationCourseId = oer.OnlineEducationCourseId
where oer.ClubId IN('K20','B67','P89')
and DateCompleted between '2013-01-01' and '2014-01-01'
group by oec.CourseTitle,oec.OnlineEducationCourseId

LINQ中的相同SQL查询

var r = (from oer in db.OnlineEducationRegistrations
join oec in db.OnlineEducationCourses on oer.OnlineEducationCourseId equals
oec.OnlineEducationCourseId
where (oer.ClubId.Contains(some IEnumerable collection here) && oer.DateCompleted >= start.Date && oer.DateCompleted <= end.Date)
group new { oec, oer } by new { oec.CourseTitle, oec.OnlineEducationCourseId }).ToList();