C# Fastest way to Export DataTable to Excel

When working with spreadsheets, the Microsoft Excel application is a popular spreadsheet tool designed for managing large data sets in a tabular format. It offers powerful features such as complex calculations, data visualization through charts and graphs, pivot tables, and support for automation via Visual Basic for Applications (VBA). Its robust data analysis and visualization tools have made Excel a leading choice across various industries. With Excel, you can easily create, edit, view, and share files, streamlining your data management tasks.

In C#, the DataTable object in the ADO.NET library represents tabular data within a program, much like an Excel worksheet. It organizes data into rows and columns, allowing for easy manipulation and export. Just like Excel, DataTable supports filtering, sorting, and formatting options, making it a go-to tool for managing data ranges in C#. However, DataTable is created at runtime, and its data is lost when the application is closed, unless exported to a more permanent format, such as an Excel file or CSV file.

Today, we will be exploring how to create a DataTable in C# and export its data to an Excel document using IronXL, a powerful .NET Excel library.

IronXL: A .NET Excel Library

IronXL is a C# .NET library, which simplifies the process of creating Excel files. With IronXL, you can create new spreadsheets, edit existing ones, work with Excel formulas, style your spreadsheet's cells, and more. Its rich range of features makes working with Excel files programmatically a breeze, and, most importantly, IronXL works without Microsoft Office Interop. This means no need to install Microsoft Office or any other special dependencies.

With IronXL, you can save or export data in different formats like XLS and XLSX, CSV data and TSV, JSON, XML and HTML, Binary and Byte Array. It also boasts strong workbook security features such as adding permissions & passwords and allows you to edit the workbook metadata.

Steps to Export Data from Datatable to Excel File

Prerequisites

To use IronXL in exporting data from datatable to Excel file in C#, we need the following components to be installed on local computer. Let's have a look at them one by one.

1. Visual Studio - Visual Studio is the IDE for C# programming and must be installed. You can download and install latest version from Visual Studio website.

   • Once the IDE is set up, a Console application/Windows form needs to be created which will help to export datatable to Excel. Following screenshots show how to create a project.

     

     Now, choose your project type. In our example, we will be creating a Console App.

     

     Name your project and choose the location it will be saved to.

     

     Finally, choose your .NET Framework, and click "Create".

     

     After clicking Create in the last screenshot, the project with the name "DemoApp" is created.

2. IronXL library - The IronXL library must be downloaded and installed in the Visual Studio project. There are multiple ways to do it.

   • Using Visual Studio - It provides the NuGet Package Manager to install IronXL. You can access it via the Tools menu or Solution Explorer. The following screenshots help to install IronXL. First, navigate to "Tools" in the top bar, or right-click within your solution explorer.

     

     

     Go to Manage NuGet Packages for Solution, and search for IronXL. Then, you just have to press "Install" and the IronXL library will be added to your project.

     

   • Developer Command Prompt - Open the Developer Command Prompt either from the Visual Studio Tools menu or from the Visual Studio folder. Type the following command to download and install IronXL in your project:

     PM > Install-Package IronXL.Excel

     PM > Install-Package IronXL.Excel

     'INSTANT VB TODO TASK: The following line uses invalid syntax:
     'PM > Install-Package IronXL.Excel

     VB   C#
   • Directly from NuGet Package Manager - Navigate to this URL https://www.nuget.org/packages/ironxl.excel/ to download IronXL.

3. Add Necessary Namespaces - To create datatable and use IronXL, both should be referenced on top of the Program.cs file.

   using IronXL; //add reference...
   using System.Data;

   using IronXL; //add reference...
   using System.Data;

   Imports IronXL 'add reference...
   Imports System.Data

   VB   C#

Once all the prerequisites are fulfilled, it's time to export data from datatable to Excel sheet.

Create a DataTable in C#

The following code creates a new data table with two column headers and multiple rows:

//new datatable dt...
DataTable dt = new DataTable();
//add column names...
dt.Columns.Add("Animal");
dt.Columns.Add("Sound");
dt.Rows.Add("Lion", "Roars"); // first row...
dt.Rows.Add("Dog", "Barks");
dt.Rows.Add("Cat", "Meows");
dt.Rows.Add("Goat", "Bleats");
dt.Rows.Add("Wolf", "Howls");
dt.Rows.Add("Cheetah", "Purrs");

//new datatable dt...
DataTable dt = new DataTable();
//add column names...
dt.Columns.Add("Animal");
dt.Columns.Add("Sound");
dt.Rows.Add("Lion", "Roars"); // first row...
dt.Rows.Add("Dog", "Barks");
dt.Rows.Add("Cat", "Meows");
dt.Rows.Add("Goat", "Bleats");
dt.Rows.Add("Wolf", "Howls");
dt.Rows.Add("Cheetah", "Purrs");

'new datatable dt...
Dim dt As New DataTable()
'add column names...
dt.Columns.Add("Animal")
dt.Columns.Add("Sound")
dt.Rows.Add("Lion", "Roars") ' first row...
dt.Rows.Add("Dog", "Barks")
dt.Rows.Add("Cat", "Meows")
dt.Rows.Add("Goat", "Bleats")
dt.Rows.Add("Wolf", "Howls")
dt.Rows.Add("Cheetah", "Purrs")

First, we create a new DataTable called "dt". Then, using Columns.Add we can add a specified number of columns to the data table by name, in our example, we have two columns called "Animal" and "Sound". We then use Rows.Add to add new rows, placing the content for each row within the brackets. The content is broken by commas, separating each string by column.

Create Excel File using IronXL in C#

When creating Excel file types from scratch using IronXL is a two step process and very easy to implement in C#. IronXL first creates an Excel workbook and then helps add worksheet to it. The following sample code demonstrates how to create a workbook along with the worksheet:

//create new workbook...
WorkBook wb = WorkBook.Create(ExcelFileFormat.XLSX);
WorkSheet ws = wb.DefaultWorkSheet;

//create new workbook...
WorkBook wb = WorkBook.Create(ExcelFileFormat.XLSX);
WorkSheet ws = wb.DefaultWorkSheet;

'create new workbook...
Dim wb As WorkBook = WorkBook.Create(ExcelFileFormat.XLSX)
Dim ws As WorkSheet = wb.DefaultWorkSheet

Exporting Data from DataTable to Excel Worksheet using IronXL

Utilizing IronXL to add values to worksheet streamlines the entire process, with it being able to carry out this task with minimal code. Here we will learn to export data from the datatable created in the previous section to the newly created Excel worksheet. Let's have a look at the code step by step.

Add column header to the Excel Worksheet

ws["A1"].Value = dt.Columns[0].ToString();
ws["B1"].Value = dt.Columns[1].ToString();
int rowCount = 2;

ws["A1"].Value = dt.Columns[0].ToString();
ws["B1"].Value = dt.Columns[1].ToString();
int rowCount = 2;

ws("A1").Value = dt.Columns(0).ToString()
ws("B1").Value = dt.Columns(1).ToString()
Dim rowCount As Integer = 2

In above code, the Excel sheet column "A1" is assigned the value from the datatable column 1 at index 0 and next Excel column "B1" value is assigned from column 2 at index 1 in the datatable. The rowCount variable is set to a value 2 for reading rows from datatable starting from row two, this ensures we don't count the header row.

Add rows to the Excel Worksheet

The following code will read each row from the datatable and assign it to new row in Excel file:

foreach (DataRow row in dt.Rows)
{
    ws["A" + (rowCount)].Value = row[0].ToString();
    ws["B" + (rowCount)].Value = row[1].ToString();
    rowCount++;
}

foreach (DataRow row in dt.Rows)
{
    ws["A" + (rowCount)].Value = row[0].ToString();
    ws["B" + (rowCount)].Value = row[1].ToString();
    rowCount++;
}

For Each row As DataRow In dt.Rows
	ws("A" & (rowCount)).Value = row(0).ToString()
	ws("B" & (rowCount)).Value = row(1).ToString()
	rowCount += 1
Next row

The rowCount variable is incremented every time so that a new row is read from the datatable to Excel worksheet cells in the above code.

Save Excel File

Finally, save the Excel file using the SaveAs() method.

wb.SaveAs("DataTable_to_Excel_IronXL.xlsx");

wb.SaveAs("DataTable_to_Excel_IronXL.xlsx");

wb.SaveAs("DataTable_to_Excel_IronXL.xlsx")

The file can be saved in other formats as well e.g CSV (Comma Separated Values), JSON, XML.

wb.SaveAsCsv("DataTable_to_Excel_IronXL.csv");
wb.SaveAsJson("DataTable_to_Excel_IronXL.json");
wb.SaveAsXml("DataTable_to_Excel_IronXL.xml");

wb.SaveAsCsv("DataTable_to_Excel_IronXL.csv");
wb.SaveAsJson("DataTable_to_Excel_IronXL.json");
wb.SaveAsXml("DataTable_to_Excel_IronXL.xml");

wb.SaveAsCsv("DataTable_to_Excel_IronXL.csv")
wb.SaveAsJson("DataTable_to_Excel_IronXL.json")
wb.SaveAsXml("DataTable_to_Excel_IronXL.xml")

You can also save it with custom delimiter.

Output

The final output of the file looks like this:

Summary

In this article, we demonstrated how to create a DataTable with columns and rows in C#, followed by generating an Excel workbook with a default worksheet using IronXL. We then successfully exported the tabular data from the DataTable into an Excel file and saved it in the .xlsx format.

IronXL is a user-friendly C# library that allows developers to work with Excel files seamlessly, even without having MS Excel installed. It supports exporting data from various formats, such as CSV files, for further manipulation and calculation.

To learn more about IronXL and its robust feature set, be sure to check out its extensive documentation. Want to try it out for yourself? IronXL also provides a free trial with full access to all features, so you can start exploring how this powerful library can improve your spreadsheet projects right away!