linq left join datatable and oder by the null value

Question

var query = from detail in dsApp.AsEnumerable() 
     join rate in dsRate.AsEnumerable() 
     on detail.Field<string>("ApplicationName") equals 
       rate.Field<string>("AppName") 
     into g 
     from h in g.DefaultIfEmpty() 
     orderby ... 
     select new { A = detail, B = (h==null? 0: h.Field<int>("num")) }; 

对于上面的查询，我该如何命令B？ 谢谢

Answer 1

var query = from detail in dsApp.AsEnumerable() 
    join rate in dsRate.AsEnumerable() 
    on detail.Field<string>("ApplicationName") equals 
      rate.Field<string>("AppName") 
    into g 
    from h in g.DefaultIfEmpty() 
    select new { A = detail, B = (h==null? 0: h.Field<int>("num")) } into Tmp 
    orderby Tmp.num 
    select new { A = Tmp.A, B = Tmp.B) }