I need to write (using C#, Asp.net 2010) large amount of data (300,000 rows) from DB to Excel (2010). And it should also create around 20 sheets dynamically. So the final Excel workbook will have 15,000 rows per sheet and 20 sheets. I tried using Open XML (DOM) but it took heaps of time and I gave it up after waiting around 40mins but got no sign of output. Also I tried to follow Brian Jone's post about how to use OpenXmlReader and OpenXmlWriter to copy a worksheet and add rows to it. But I do not know how to add sheets using that methodology.
Any help would greatly be appreciated.