/// <summary>
///获得多个数据到St扩展属性udens类的
/// </summary>
/// <param name="classId"></param>
/// <returns></returns>
public List<Students> GetStuList(int classId)
{
//根据ClassId从StudentClass中取ClassName,并给Student类中的扩展属性ClassName
return Db.Queryable<Students, StudentClass>((stu, stuClass) => new object[] { JoinType.Inner, stu.ClassId == stuClass.ClassId })
.Where(stu => stu.ClassId == classId).Select((stu,stuClass)=>new Students() {StudentName=stu.StudentName.SelectAll(), ClassName=stuClass.ClassName }).ToList();
}