What I need to do is retrieve data from the SQL Server, then draw several tables(MS Excel table like designs not data tables) inside a worksheet.
So it is impossible to write data inside my Excel file using this method.
(please see attachment)
As you can see, there are several tables inside the sample.
The number of rows inside a table is not fix, sometimes it contains 1 row but usually it may contain hundreds to thousands of rows.
If the number of rows is that large, the extraction of reports(creating xls files) will be very slow(please read previous posts).
The application should generate 16+ .xls files contains 2-6 worksheets contains 10+ tables and each tables contains 100-1,000 rows and other worksheets will contain 5+ charts.
If you analyze, the extraction of reports will be very slow if I am going to insert data cell-by-cell from my query.