How to delete multiple rows in a DataTable?

Question

Hi,

How can I delete specific DataRows within a loop of a DataTable rows which meet a custom condition -lets say the rows having an index of even number-? (Without using LINQ)

Thanks

Answer 1

Try something like this example

DataTable table = new DataTable();
table.Columns.Add("Foo",typeof(int));
for (int i = 0; i < 10; i++)
    table.Rows.Add(i);

for (int i = table.Rows.Count -1; i >=0; i--)
{
    // sample removes all even foos
    if ((int)table.Rows[i]["Foo"] % 2 == 0)
        table.Rows.RemoveAt(i);
}

Answer 2

It depends on what you mean by 'delete'.

If you mean mark them as deleted, just call the Delete() method on each row as you visit it in your loop. You then need to call AcceptChanges() on the data table to finalize the delete - presumably after you update your database (if one is involved).

foreach( DataRow row in someTable.Rows )
{
    if( /* your condition here */ )
        row.Delete();
}
someTable.AcceptChanges();

If you mean remove it from the DataTable, then you need to do so in two passes:

List<DataRow> rowsToDelete = new List<DataRow>();
foreach( DataRow row in someTable.Rows )
{
    if( /* your condition here */ )
    {
        rowsToDelete.Add( row );
    }
}

foreach( DataRow row in rowsToDelete )
{
    someTable.Rows.Remove( row );
}

It's worth pointing out that you can always use the first method to remove rows - since marking rows as Deleted and then accepting changes will automatically remove them from the table. But, sometimes it is more clear and efficient to simply remove the DataRow objects from the Rows collection.

Answer 3

try iterating over the result of Select(). This is pretty similar to other answers, but I find it the most direct

DataRow[] r = table.Select();
for (int i = 0; i < r.Length; i++)
{
    if (i % 2 == 0)
        r[i].Delete();
}

Answer 4

try this

foreach(DataRow oRow in YourDataTable.Rows)
{
  if ("Check You Condition")
   {
      YourDataTable.Rows.Remove(oRow);
   }
}

Answer 5

The other way is

    DataRow[] DrArrCheck = DataTableName.Select("ID > 0");
    foreach(DataRow DrCheck in DrArrCheck)
    {
        DataTableName.Rows.Remove(DrCheck);
    }