Best way to copy Data from one DataTable to another DataTable with diffrent structure

Question

I am copying data from DataTable to another DataTable with a structure. I have to hardcode columns number in the loop and copy the data in object array.

What will be the

Answer 1

I'm not 100% sure why you want to copy the data to an array before putting it into the VendorInvoiceTable, but either way:

IEnumerable<DataRow> query = from vendInv in VendorInvoiceStagingTable.AsEnumerable()
                             where vendInv.Field<string>(VendInvoice.Number) == InvoiceHeader
                             select vendInv;

// Would this be ok?
VendorInvoiceTable.Rows.Add(query.First().ItemArray);

// ...or if not, how about this?
object[] sourceData = query.First().ItemArray;
object[] targetData = new object[sourceData.Length];
sourceData.CopyTo(targetData, 0);
VendorInvoiceTable.Rows.Add(targetData);

Answer 2

Probably, check out Adapter pattern, it will allow you to adapt the structure of one data table to another. A simple explanation and sample code can be found at Dofactory.