asp.net - Restructuring (transposing) datatable in c# -

i have datatable below

    tablename   rowid   columnname  columnvalue               1       c1          v1               1       c2          v2               2       c1          v3               2       c2          v4 

i want transpose below structure

    tablename rowid c1 c2             1     v1 v2             2     v3 v4 

how in c#?

i prepared little complex solution, not require values hidden inside columnname column of source datatable:

source datatable preparation:

var source = new datatable(); source.columns.add(new datacolumn("tablename", typeof(string))); source.columns.add(new datacolumn("rowid", typeof(int))); source.columns.add(new datacolumn("columnname", typeof(string))); source.columns.add(new datacolumn("columnvalue", typeof(string)));  source.rows.add("a", 1, "c1", "v1"); source.rows.add("a", 1, "c2", "v2"); source.rows.add("a", 2, "c1", "v3"); source.rows.add("a", 2, "c2", "v4"); 

target datatable preparation:

var target = new datatable(); target.columns.add(new datacolumn("tablename", typeof(string))); target.columns.add(new datacolumn("rowid", typeof(int))); 

helper linq query:

var query = r in source.asenumerable()             let = new             {                 tablename = r.field<string>("tablename"),                 id = r.field<int>("rowid"),                 columnname = r.field<string>("columnname"),                 columnvalue = r.field<string>("columnvalue")             }             group new { i.tablename, i.id } g             select g; 

inserting data target datatable:

foreach (var item in query) {     var newrow = target.newrow();      // static columns     newrow["tablename"] = item.key.tablename;     newrow["rowid"] = item.key.id;      // dynamic columns     foreach (var c in item)     {         if(!target.columns.contains(c.columnname))         {             target.columns.add(new datacolumn(c.columnname, typeof(string)));         }          newrow[c.columnname] = c.columnvalue;     }      target.rows.add(newrow); }