用lambda表达式写左联查询的示例

需要完成的查询逻辑：A表内联B表，B表左联C表，A表左联D表，并且 C表的TotalCount>23,D表的ClassHour>8,最后查出A表的Id,代码如下：

IQueryable<int> biz_AAA_IdQueryable = uow.Biz_AAA.GetAll()
                              .Join(uow.Biz_BBB.GetAll(), a => a.CertificateId, b => b.Id, (a, b) => new { a, b })
                              .GroupJoin(uow.Biz_CCC.GetAll(), o => o.b.IDNumber, c => c.IDNumber, (o, c) => new { o.a, o.b, c })
                              .SelectMany(cc => cc.c.DefaultIfEmpty(), (o, cc) => new { o.a, o.b, c = cc })
                              .GroupJoin(uow.Biz_DDD.GetAll(), o => o.a.Id, d => d.CertificateDelayApplyRecordId, (o, d) => new { o.a, o.b, o.c, d })
                              .SelectMany(dd => dd.d.DefaultIfEmpty(), (o, dd) => new { o.a, o.b, o.c, d = dd })
                              .Select(o => new
                              {
                                  CertificateDelayApplyRecordId = o.a.Id,
                                  CreateDate = o.a.CreateDate,
                                  OnLineClassHour = o.c == null ?  : o.c.TotalCount,
                                  OffLineClassHour = o.d == null ?  : o.d.ClassHour
                              })
                        .Where(o => o.OnLineClassHour >  && o.OffLineClassHour > 8)
                        .Select(o => o.CertificateDelayApplyRecordId);

希望写的东西，能够帮到别人，自己在网上找了很久，用别人的写法，生成的时候，总是报错，后面自己研究了下，发现这个写法是OK的，生成的sql语句是我想要的语句。