Question

I want to export data from data table to Excel file. I need to save the file on server. I am using the console application for this project.

Answer 1

Since you haven’t mentioned if excel is installed, i recommend EPPlus to create the excel file. It has a convenient method LoadFromDataTable:

using (var pck = new ExcelPackage())
{
    var ws = pck.Workbook.Worksheets.Add("Worksheet-Name");
    ws.Cells["A1"].LoadFromDataTable(dataTable1, true, OfficeOpenXml.Table.TableStyles.Medium1);
    using(var fileStream = File.Create(path))
        pck.SaveAs(fileStream);
}

Edit i’ve only just seen that you have tagged export-to-csv.

var lines = dataTable1.AsEnumerable()
    .Select(r => string.Join(",", r.ItemArray));
string csv = string.Join(Environment.NewLine, lines);

File.AppendAllText(path, csv);