多表关联

C# code

    var result = from s in stock                         join r in report on s["ProductId"] equals r["ProductId"] into sr                         join p in product on s["ProductId"].ToString().ToLower() equals p["ProductId"].ToString().ToLower() into rp                        

看代码，不废话，这里s是主表，但是我现在又要关联1个表w，这个表里面有一个字段跟r表里面字段warehouseid关联，可是这里r不是主表，根本不能关联到，请问用什么办法管理这两个副表呢，本人小菜，希望原谅。


[解决办法]
上面有个错

C# code

var result = from s in stock              join r in report on s["ProductId"] equals r["ProductId"] into sr              from srs in sr.DefaultIfEmpty()               join p in product on s["ProductId"].ToString().ToLower() equals p["ProductId"].ToString().ToLower() into rp              from rps in rp.DefaultIfEmpty()              join w in w_table on srs.warehouseid equals w.ID into wr              from wrs in wr.DefaultIfEmpty()