海风cuao

摘要： var ReportOrderings = from A in resultA join R in resulR on new { A.DCode, A.AContent } equals new { R.DCode, R.Content } into C from R in C.DefaultIfEmpty() //左连接 select new { DCode=A.DCode, AContent= A.AContent, ACount= A.ACount, RCount = R == null ? 0 : R.RCount //左连接时,R表中不符合条件则R会为Null... 阅读全文