c# - How to perform group by on datatable field with relationship define between 2 datatables? -

i having 2 datatables following records in dataset:

dtvariant:

name        type        status variant1    add          active variant2    division     active 

dtsubvariant:

name       type           subvariantname  variant1    add            sub1 variant1    add            sub2 variant1    add            sub3 variant2    division       sub1 variant2    division       sub2 variant2    division       sub3 variant2    division       sub4 

now want subvariants list variant type , variants status active below:

add:sub1,sub2,sub3  division:sub1,sub2,sub3,sub4 

here have build relationship between columns name , type between 2 datatables below:

ds1.relations.add("myrelation", dtvariant, dtsubvariant, false); 

query:

var data = (from c in ds1.tables["dtvariant"].asenumerable()    .where c.field<string>("status")=="active"            group c new { type = c.field<string>("type") } grp                   select new            {                  type= grp.key.type,                   names=                dp in c.getchildrows("myrelation")//not getting method            }).tolist(); 

but when trying this:

from dp in c.getchildrows("myrelation") //i not getting getchildrows method. 

can me this??

var result = ds1.tables["dtsubvariant"].asenumerable()              .groupby(i => i.type)              .select(x=>new                    {                     type= i.key.type,                     subvariantlist=i.select(x=>x.subvariantname).toarray()                    }).tolist(); 

you have info in dtsubvariant, , can use query it.