public static IQueryable<ProdType> GetDistinctProdType(

    this IQueryable<ProdInfo> query,

    int categoryId)

{

    return (from p in query

            where p.CatID == categoryId

            select p.Type).Distinct();

}

var _dbLogList = (from d in _context.pu_Synchronize_Log

                              join cd in _context.pu_Synchronize_Child_Log

                              on d.Synchronize_Log_Id equals cd.Synchronize_Log_Id

                              where cd.Mobile_Device_Id == preference.DId && cd.Synchronize_Status == "OPEN"

                             && !d.Is_Deleted && !cd.Is_Deleted

                             select new

                             {

                                 d.Service_Name,

                            }).Distinct().ToList();