摘要：
users：用户表Orderss:订单表U_O：用户和订单的中间表OrdersEntities1 oe = new OrdersEntities1(); var result = from user in oe.Users join o_u in oe.U_OC on user.Id equals o_u.UId into o_uList from o_u1 in o_uList.DefaultIfEmpty() join o in oe.Orderss on o_u1.OId equals o.Id into o_u1List from o_u2 in o_u1List.DefaultIf. 阅读全文
