DataTable, How to conditionally delete rows

Question

I'm engaged in a C# learning process and it is going well so far. I however just now hit my first "say what?" moment.

The DataTable offers random row access to its Rows collection, not only through typical collections behavior, but also through DataTable.Select. However I cannot seem to be able to tie this ability to DataRow.Delete. So far this is what it seems I need to do in order to conditionally delete one or more rows from a table.

int max = someDataTable.Rows.Count - 1; for(int i = max; i >= 0; --i) {     if((int)someDataTable.Rows[i].ItemArray[0] == someValue)     {         someDataTable.Rows[i].BeginEdit();         someDataTable.Rows[i].Delete();     }     else         break; } someDataTable.AcceptChanges(); 

But I'm not happy with this code. Neither I'm convinced. I must be missing something. Am I really forced to hit the Rows collection sequentially if I need to delete one or more rows conditionally?

(don't mind the inverted for. I'm deleting from the end of the datatable. So it's ok)

Answer 1

You could query the dataset and then loop the selected rows to set them as delete.

var rows = dt.Select("col1 > 5"); foreach (var row in rows)     row.Delete(); 

... and you could also create some extension methods to make it easier ...

myTable.Delete("col1 > 5");  public static DataTable Delete(this DataTable table, string filter) {     table.Select(filter).Delete();     return table; } public static void Delete(this IEnumerable<DataRow> rows) {     foreach (var row in rows)         row.Delete(); } 

Answer 2

Here's a one-liner using LINQ and avoiding any run-time evaluation of select strings:

someDataTable.Rows.Cast<DataRow>().Where(     r => r.ItemArray[0] == someValue).ToList().ForEach(r => r.Delete());