How can I add a new column and data to a datatable that already contains data?

Question

How do I add a new DataColumn to a DataTable object that already contains data?

PseudoCode

//call SQL helper class to get initial data  DataTable dt = sql.ExecuteDataTable("sp_MyProc");  dt.Columns.Add("NewColumn", type(System.Int32));  foreach(DataRow row in dr.Rows) {     //need to set value to NewColumn column } 

Answer 1

Just keep going with your code - you're on the right track:

//call SQL helper class to get initial data  DataTable dt = sql.ExecuteDataTable("sp_MyProc");  dt.Columns.Add("NewColumn", typeof(System.Int32));  foreach(DataRow row in dt.Rows) {     //need to set value to NewColumn column     row["NewColumn"] = 0;   // or set it to some other value }  // possibly save your Dataset here, after setting all the new values 

Answer 2

Should it not be foreach instead of for!?

//call SQL helper class to get initial data   DataTable dt = sql.ExecuteDataTable("sp_MyProc");   dt.Columns.Add("MyRow", **typeof**(System.Int32));   foreach(DataRow dr in dt.Rows)  {      //need to set value to MyRow column      dr["MyRow"] = 0;   // or set it to some other value  }