USING IRONXL

Importing an Excel File into DataTable with IronXL

Published:February 15, 2026

C# Import Excel File into DataTable with IronXL

It’s no secret that manually parsing Excel files is rarely the highlight of a developer’s day. We’ve all been there, wrestling with legacy OLEDB connection strings or trying to map unstructured spreadsheet data into something your .NET application actually understands.

The DataTable in C# is the great equalizer. It acts as the perfect bridge, turning those rows and columns into a familiar structure ready for LINQ queries, DataGrid binding, or a quick trip to a SQL database.

IronXL takes the heavy lifting out of this process. Instead of complex configurations, it uses a single, intuitive ToDataTable method to handle the conversion. Whether you're building a reporting tool or a data migration script, here is how you can import Excel data effortlessly.

Want to follow along? Use the IronXL free trial to try this powerful library out for yourself.

How Can You Import an Excel File into a DataTable in C#?

To C# import Excel file into DataTable, load the workbook using WorkBook.Load, access the target worksheet, and call the ToDataTable method. This approach works with XLSX files, XLS, XLSM, and CSV formats. Ensure you reference the following namespaces to access the necessary classes.

Install IronXL via NuGet Package Manager the following command in Visual Studio using the NuGet Package Manager:

Install-Package IronXL.Excel

Then, use this concise code snippet to get your data moving:

using IronXL;
using System;
using System.Data;
class Program
{
    static void Main(string[] args)
    {
        // Load the Excel file from the specified path
        string filePath = "sales-data.xlsx";
        WorkBook workbook = WorkBook.Load(filePath);
        // Access the first worksheet in the workbook
        WorkSheet worksheet = workbook.DefaultWorkSheet;
        // Convert worksheet to DataTable with first row as column headers
        DataTable dt = worksheet.ToDataTable(true);
        // Display the imported data
        foreach (DataRow row in dt.Rows)
        {
            Console.WriteLine(string.Join(" | ", row.ItemArray));
        }
    }
}

using IronXL;
using System;
using System.Data;
class Program
{
    static void Main(string[] args)
    {
        // Load the Excel file from the specified path
        string filePath = "sales-data.xlsx";
        WorkBook workbook = WorkBook.Load(filePath);
        // Access the first worksheet in the workbook
        WorkSheet worksheet = workbook.DefaultWorkSheet;
        // Convert worksheet to DataTable with first row as column headers
        DataTable dt = worksheet.ToDataTable(true);
        // Display the imported data
        foreach (DataRow row in dt.Rows)
        {
            Console.WriteLine(string.Join(" | ", row.ItemArray));
        }
    }
}

Imports IronXL
Imports System
Imports System.Data

Module Program
    Sub Main(args As String())
        ' Load the Excel file from the specified path
        Dim filePath As String = "sales-data.xlsx"
        Dim workbook As WorkBook = WorkBook.Load(filePath)
        ' Access the first worksheet in the workbook
        Dim worksheet As WorkSheet = workbook.DefaultWorkSheet
        ' Convert worksheet to DataTable with first row as column headers
        Dim dt As DataTable = worksheet.ToDataTable(True)
        ' Display the imported data
        For Each row As DataRow In dt.Rows
            Console.WriteLine(String.Join(" | ", row.ItemArray))
        Next
    End Sub
End Module

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Output

Importing an Excel File into DataTable with IronXL: Image 1 - Excel file imported to a DataTable

The WorkBook.Load method reads the Excel file from the string filePath location and creates a workbook object containing all Excel sheet data. The ToDataTable(true) parameter indicates that the first row contains column headers, which are automatically used as the Data Table column names.

What Is the Best Method for Reading Excel File Data into a DataTable?

Reading Excel file content efficiently requires handling both header rows and raw data scenarios. IronXL's ToDataTable method accepts a boolean parameter that determines whether the first row is treated as column names or as data. Note that handling extended properties or converting complex cell types may require additional configuration, but the default method handles most cases robustly.

using IronXL;
using System.Data;
// Load workbook from file path
string filePath = @"C:\Data\inventory.xlsx";
WorkBook workbook = WorkBook.Load(filePath);
WorkSheet worksheet = workbook.WorkSheets[0];
// First row as headers (true) or as data (false)
DataTable dataTableWithHeaders = worksheet.ToDataTable(true);
DataTable dataTableWithoutHeaders = worksheet.ToDataTable(false);
// Process each row in the DataTable
foreach (DataRow row in dataTableWithHeaders.Rows)
{
    for (int i = 0; i < dataTableWithHeaders.Columns.Count; i++)
    {
        object value = row[i];
        Console.Write($"{value}\t");
    }
    Console.WriteLine();
}

using IronXL;
using System.Data;
// Load workbook from file path
string filePath = @"C:\Data\inventory.xlsx";
WorkBook workbook = WorkBook.Load(filePath);
WorkSheet worksheet = workbook.WorkSheets[0];
// First row as headers (true) or as data (false)
DataTable dataTableWithHeaders = worksheet.ToDataTable(true);
DataTable dataTableWithoutHeaders = worksheet.ToDataTable(false);
// Process each row in the DataTable
foreach (DataRow row in dataTableWithHeaders.Rows)
{
    for (int i = 0; i < dataTableWithHeaders.Columns.Count; i++)
    {
        object value = row[i];
        Console.Write($"{value}\t");
    }
    Console.WriteLine();
}

Imports IronXL
Imports System.Data

' Load workbook from file path
Dim filePath As String = "C:\Data\inventory.xlsx"
Dim workbook As WorkBook = WorkBook.Load(filePath)
Dim worksheet As WorkSheet = workbook.WorkSheets(0)

' First row as headers (true) or as data (false)
Dim dataTableWithHeaders As DataTable = worksheet.ToDataTable(True)
Dim dataTableWithoutHeaders As DataTable = worksheet.ToDataTable(False)

' Process each row in the DataTable
For Each row As DataRow In dataTableWithHeaders.Rows
    For i As Integer = 0 To dataTableWithHeaders.Columns.Count - 1
        Dim value As Object = row(i)
        Console.Write($"{value}" & vbTab)
    Next
    Console.WriteLine()
Next

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Output

Importing an Excel File into DataTable with IronXL: Image 2 - Output for importing and reading an Excel file into a DataTable

This flexibility makes IronXL ideal for processing Excel spreadsheet files regardless of their structure. Unlike the EPPlus package or traditional methods requiring new OleDbDataAdapter instances, IronXL handles the conversion in a single method call. The library supports .NET Core, .NET Framework, and cross-platform deployment without requiring Microsoft Excel installation.

How Do You Convert Multiple Excel Worksheets to a DataSet?

When your Excel workbook contains multiple sheets, converting to a DataSet preserves each Excel worksheet as a separate DataTable within the collection. This approach is essential for reporting applications and multi-sheet data processing.

using IronXL;
using System;
using System.Data;
// Load multi-sheet workbook
WorkBook workbook = WorkBook.Load("quarterly-reports.xlsx");
// Convert entire workbook to DataSet (each sheet becomes a DataTable)
DataSet dataset = workbook.ToDataSet();
// Iterate through all tables in the DataSet
foreach (DataTable table in dataset.Tables)
{
    Console.WriteLine($"Sheet: {table.TableName}");
    Console.WriteLine($"Rows: {table.Rows.Count}, Columns: {table.Columns.Count}");
    foreach (DataRow row in table.Rows)
    {
        Console.WriteLine(string.Join(", ", row.ItemArray));
    }
}

using IronXL;
using System;
using System.Data;
// Load multi-sheet workbook
WorkBook workbook = WorkBook.Load("quarterly-reports.xlsx");
// Convert entire workbook to DataSet (each sheet becomes a DataTable)
DataSet dataset = workbook.ToDataSet();
// Iterate through all tables in the DataSet
foreach (DataTable table in dataset.Tables)
{
    Console.WriteLine($"Sheet: {table.TableName}");
    Console.WriteLine($"Rows: {table.Rows.Count}, Columns: {table.Columns.Count}");
    foreach (DataRow row in table.Rows)
    {
        Console.WriteLine(string.Join(", ", row.ItemArray));
    }
}

Imports IronXL
Imports System
Imports System.Data

' Load multi-sheet workbook
Dim workbook As WorkBook = WorkBook.Load("quarterly-reports.xlsx")
' Convert entire workbook to DataSet (each sheet becomes a DataTable)
Dim dataset As DataSet = workbook.ToDataSet()
' Iterate through all tables in the DataSet
For Each table As DataTable In dataset.Tables
    Console.WriteLine($"Sheet: {table.TableName}")
    Console.WriteLine($"Rows: {table.Rows.Count}, Columns: {table.Columns.Count}")
    For Each row As DataRow In table.Rows
        Console.WriteLine(String.Join(", ", row.ItemArray))
    Next
Next

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Output

Importing an Excel File into DataTable with IronXL: Image 3 - Output for importing a multi-sheet Excel file to DataSet

The ToDataSet method creates a new DataSet containing DataTable objects for every worksheet. Each table's TableName property reflects the original Excel sheet name, making it easy to reference specific data during processing.

How Can You Import Data from Excel to a Database?

A common workflow involves reading Excel file data and inserting it into a database system. The DataTable structure integrates seamlessly with ADO.NET for database operations.

using IronXL;
using System.Data;
using System.Data.SqlClient;
string filePath = @"C:\imports\customer-data.xlsx";
WorkBook workbook = WorkBook.Load(filePath);
WorkSheet worksheet = workbook.DefaultWorkSheet;
// Convert Excel data to DataTable
DataTable dt = worksheet.ToDataTable(true);
// Validate data before database insert
if (dt == null || dt.Rows.Count == 0)
{
    Console.WriteLine("No data to import");
    return;
}
// Insert into database using SqlBulkCopy
string connectionString = "Server=.;Database=Sales;Trusted_Connection=True;";
using (SqlConnection connection = new SqlConnection(connectionString))
{
    connection.Open();
    using (SqlBulkCopy bulkCopy = new SqlBulkCopy(connection))
    {
        bulkCopy.DestinationTableName = "Customers";
        bulkCopy.WriteToServer(dt);
    }
}
Console.WriteLine($"Imported {dt.Rows.Count} records successfully");

using IronXL;
using System.Data;
using System.Data.SqlClient;
string filePath = @"C:\imports\customer-data.xlsx";
WorkBook workbook = WorkBook.Load(filePath);
WorkSheet worksheet = workbook.DefaultWorkSheet;
// Convert Excel data to DataTable
DataTable dt = worksheet.ToDataTable(true);
// Validate data before database insert
if (dt == null || dt.Rows.Count == 0)
{
    Console.WriteLine("No data to import");
    return;
}
// Insert into database using SqlBulkCopy
string connectionString = "Server=.;Database=Sales;Trusted_Connection=True;";
using (SqlConnection connection = new SqlConnection(connectionString))
{
    connection.Open();
    using (SqlBulkCopy bulkCopy = new SqlBulkCopy(connection))
    {
        bulkCopy.DestinationTableName = "Customers";
        bulkCopy.WriteToServer(dt);
    }
}
Console.WriteLine($"Imported {dt.Rows.Count} records successfully");

Imports IronXL
Imports System.Data
Imports System.Data.SqlClient

Module Module1
    Sub Main()
        Dim filePath As String = "C:\imports\customer-data.xlsx"
        Dim workbook As WorkBook = WorkBook.Load(filePath)
        Dim worksheet As WorkSheet = workbook.DefaultWorkSheet
        ' Convert Excel data to DataTable
        Dim dt As DataTable = worksheet.ToDataTable(True)
        ' Validate data before database insert
        If dt Is Nothing OrElse dt.Rows.Count = 0 Then
            Console.WriteLine("No data to import")
            Return
        End If
        ' Insert into database using SqlBulkCopy
        Dim connectionString As String = "Server=.;Database=Sales;Trusted_Connection=True;"
        Using connection As New SqlConnection(connectionString)
            connection.Open()
            Using bulkCopy As New SqlBulkCopy(connection)
                bulkCopy.DestinationTableName = "Customers"
                bulkCopy.WriteToServer(dt)
            End Using
        End Using
        Console.WriteLine($"Imported {dt.Rows.Count} records successfully")
    End Sub
End Module

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This code demonstrates how to load an Excel file, convert it to a DataTable, and perform a bulk database insert. The null check ensures data integrity before attempting the import operation.

How Do You Export a DataTable Back to Excel?

IronXL supports bi-directional data flow, allowing you to create Excel files from DataTable objects for reporting and data export scenarios.

using IronXL;
using System.Data;
// Create sample DataTable
DataTable dt = new DataTable("Products");
dt.Columns.Add("ProductID", typeof(int));
dt.Columns.Add("Name", typeof(string));
dt.Columns.Add("Price", typeof(decimal));
dt.Rows.Add(1, "Widget", 29.99m);
dt.Rows.Add(2, "Gadget", 49.99m);
// Create new workbook and load DataTable
WorkBook workbook = WorkBook.Create();
workbook.LoadWorkSheetsFromDataSet(new DataSet { Tables = { dt } });
// Save as Excel file
workbook.SaveAs("exported-products.xlsx");

using IronXL;
using System.Data;
// Create sample DataTable
DataTable dt = new DataTable("Products");
dt.Columns.Add("ProductID", typeof(int));
dt.Columns.Add("Name", typeof(string));
dt.Columns.Add("Price", typeof(decimal));
dt.Rows.Add(1, "Widget", 29.99m);
dt.Rows.Add(2, "Gadget", 49.99m);
// Create new workbook and load DataTable
WorkBook workbook = WorkBook.Create();
workbook.LoadWorkSheetsFromDataSet(new DataSet { Tables = { dt } });
// Save as Excel file
workbook.SaveAs("exported-products.xlsx");

Imports IronXL
Imports System.Data

' Create sample DataTable
Dim dt As New DataTable("Products")
dt.Columns.Add("ProductID", GetType(Integer))
dt.Columns.Add("Name", GetType(String))
dt.Columns.Add("Price", GetType(Decimal))
dt.Rows.Add(1, "Widget", 29.99D)
dt.Rows.Add(2, "Gadget", 49.99D)

' Create new workbook and load DataTable
Dim workbook As WorkBook = WorkBook.Create()
workbook.LoadWorkSheetsFromDataSet(New DataSet With {.Tables = {dt}})

' Save as Excel file
workbook.SaveAs("exported-products.xlsx")

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Output

Importing an Excel File into DataTable with IronXL: Image 4 - DataTable exported to Excel

The LoadWorkSheetsFromDataSet method accepts a DataSet containing your DataTable objects and creates corresponding worksheets. Learn more about exporting DataTable to Excel in the documentation.

Conclusion

IronXL transforms the complexity of Excel-to-DataTable conversion into straightforward method calls. Whether importing a single Excel worksheet or processing multi-sheet workbooks into a complete DataSet, the library handles XLSX files, data type conversion, and stream-based loading efficiently.

The combination of DataTable flexibility and IronXL's intuitive API enables powerful data workflows for database integration, reporting systems, and application data binding. Download IronXL to streamline your Excel data processing, or purchase a license for production deployment.

Get stated with IronXL now.

Jordi Bardia

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Software Engineer

Jordi is most proficient in Python, C# and C++, when he isn’t leveraging his skills at Iron Software; he’s game programming. Sharing responsibilities for product testing, product development and research, Jordi adds immense value to continual product improvement. The varied experience keeps him challenged and engaged, and he ...