export Excel to DataTable using NPOI

Question

I want to read Excel Tables 2010 xlsx using NPOI and then export data to DataTables but don\'t know how to use it. Can anyone show me step by step how to export Excel to Datatab

Answer 1

I edited @Saeb Amini code to allow blank cells.

IWorkbook workbook;
using (FileStream stream = new FileStream(excelFilePath, FileMode.Open, FileAccess.Read))
{
    workbook = new HSSFWorkbook(stream);
}

ISheet sheet = workbook.GetSheetAt(0);
DataTable dt = new DataTable(sheet.SheetName);

// write header row
IRow headerRow = sheet.GetRow(0);
foreach (ICell headerCell in headerRow)
{
    dt.Columns.Add(headerCell.ToString());
}

// write the rest
int rowIndex = 0;
foreach (IRow row in sheet)
{
     // skip header row
     if (rowIndex++ == 0) continue;

     // add row into datatable
     var cells = new List();
     for (int i = 0; i < dt.Columns.Count; i++)
     {
          cells.Add(row.GetCell(i, MissingCellPolicy.CREATE_NULL_AS_BLANK));
     }

     // Columns formatted as DateTime will be printed as '01-Jul-2005', 
     // which can be converted to datetime in the SQL server.
     // select cast('01-Jul-2005' as DateTime).
     // In SQL Server we can convert DateTime to whatever string we want, for example
     // select convert(nvarchar(255), cast('01-Jul-2005' as datetime), 112) will print '20050701'.
     // http://www.sqlusa.com/bestpractices/datetimeconversion/
     dt.Rows.Add(cells.Select(c => c.ToString()).ToArray());

     // Datetimes also can be reformatted directly like this :
     // dt.Rows.Add(cells.Select(c =>
     //    c.CellType == CellType.Numeric && DateUtil.IsCellDateFormatted(c) 
     //        ? c.DateCellValue.ToString("yyyyMMdd") 
     //        : c.ToString()
     // ).ToArray());

}

//return dt;