I have a StayDormApplications table , I have a SQL as below ,
var systemFilesItem = _db.StayDormApplications.Single(r => r.Id == dormapplication.Id);
string SQL = "SELECT sum(days) days from StayDormApplications where poster = '" + LoginAccount + "' and DATEPART(MONTH, Sdate) = '"+ month_name + "' group by DATEPART(MONTH, Sdate);"; //
how to convert the SQL with (c#) LINQ?