С library read excel

ExcelDataReader

Lightweight and fast library written in C# for reading Microsoft Excel files (2.0-2007).

Please feel free to fork and submit pull requests to the develop branch.

If you are reporting an issue it is really useful if you can supply an example Excel file as this makes debugging much easier and without it we may not be able to resolve any problems.

Continuous integration

Branch	Build status
develop
master

Supported file formats and versions

Finding the binaries

It is recommended to use NuGet through the VS Package Manager Console Install-Package <package> or using the VS «Manage NuGet Packages…» extension.

As of ExcelDataReader version 3.0, the project was split into multiple packages:

Install the ExcelDataReader base package to use the «low level» reader interface. Compatible with met462, netstandard2.0 and netstandard2.1.

Install the ExcelDataReader.DataSet extension package to use the AsDataSet() method to populate a System.Data.DataSet. This will also pull in the base package. Compatible with net462, netstandard2.0 and netstandard2.1.

How to use

using (var stream = File.Open(filePath, FileMode.Open, FileAccess.Read))
{
    // Auto-detect format, supports:
    //  - Binary Excel files (2.0-2003 format; *.xls)
    //  - OpenXml Excel files (2007 format; *.xlsx, *.xlsb)
    using (var reader = ExcelReaderFactory.CreateReader(stream))
    {
        // Choose one of either 1 or 2:

        // 1. Use the reader methods
        do
        {
            while (reader.Read())
            {
                // reader.GetDouble(0);
            }
        } while (reader.NextResult());

        // 2. Use the AsDataSet extension method
        var result = reader.AsDataSet();

        // The result of each spreadsheet is in result.Tables
    }
}

Reading .CSV files

Use ExcelReaderFactory.CreateCsvReader instead of CreateReader to parse a stream of plain text with comma separated values.

See also the configuration options FallbackEncoding and AutodetectSeparators.

The input CSV is always parsed once completely to set FieldCount, RowCount, Encoding, Separator (or twice if the CSV lacks BOM and is not UTF8), and then parsed once again while iterating the row records. Throws System.Text.DecoderFallbackException if the input cannot be parsed with the specified encoding.

The reader returns all CSV field values as strings and makes no attempts to convert the data to numbers or dates. This caller is responsible for interpreting the CSV data.

Using the reader methods

The AsDataSet() extension method is a convenient helper for quickly getting the data, but is not always available or desirable to use. IExcelDataReader extends the System.Data.IDataReader and IDataRecord interfaces to navigate and retrieve data at a lower level. The most important reader methods and properties:

• Read() reads a row from the current sheet.
• NextResult() advances the cursor to the next sheet.
• ResultsCount returns the number of sheets in the current workbook.
• Name returns the name of the current sheet.
• CodeName returns the VBA code name identifier of the current sheet.
• FieldCount returns the number of columns in the current sheet.
• RowCount returns the number of rows in the current sheet. This includes terminal empty rows which are otherwise excluded by AsDataSet(). Throws InvalidOperationException on CSV files when used with AnalyzeInitialCsvRows.
• HeaderFooter returns an object with information about the headers and footers, or null if there are none.
• MergeCells returns an array of merged cell ranges in the current sheet.
• RowHeight returns the visual height of the current row in points. May be 0 if the row is hidden.
• GetColumnWidth() returns the width of a column in character units. May be 0 if the column is hidden.
• GetFieldType() returns the type of a value in the current row. Always one of the types supported by Excel: double, int, bool, DateTime, TimeSpan, string, or null if there is no value.
• IsDBNull() checks if a value in the current row is null.
• GetValue() returns a value from the current row as an object, or null if there is no value.
• GetDouble(), GetInt32(), GetBoolean(), GetDateTime(), GetString() return a value from the current row cast to their respective type.
• GetNumberFormatString() returns a string containing the formatting codes for a value in the current row, or null if there is no value. See also the Formatting section below.
• GetNumberFormatIndex() returns the number format index for a value in the current row. Index values below 164 refer to built-in number formats, otherwise indicate a custom number format.
• GetCellStyle() returns an object containing style information for a cell in the current row: indent, horizontal alignment, hidden, locked.
• The typed Get*() methods throw InvalidCastException unless the types match exactly.

CreateReader() configuration options

The ExcelReaderFactory.CreateReader(), CreateBinaryReader(), CreateOpenXmlReader(), CreateCsvReader() methods accept an optional configuration object to modify the behavior of the reader:

var reader = ExcelReaderFactory.CreateReader(stream, new ExcelReaderConfiguration()
{
    // Gets or sets the encoding to use when the input XLS lacks a CodePage
    // record, or when the input CSV lacks a BOM and does not parse as UTF8. 
    // Default: cp1252 (XLS BIFF2-5 and CSV only)
    FallbackEncoding = Encoding.GetEncoding(1252),

    // Gets or sets the password used to open password protected workbooks.
    Password = "password",

    // Gets or sets an array of CSV separator candidates. The reader 
    // autodetects which best fits the input data. Default: , ; TAB | # 
    // (CSV only)
    AutodetectSeparators = new char[] { ',', ';', 't', '|', '#' },

    // Gets or sets a value indicating whether to leave the stream open after
    // the IExcelDataReader object is disposed. Default: false
    LeaveOpen = false,

    // Gets or sets a value indicating the number of rows to analyze for
    // encoding, separator and field count in a CSV. When set, this option
    // causes the IExcelDataReader.RowCount property to throw an exception.
    // Default: 0 - analyzes the entire file (CSV only, has no effect on other
    // formats)
    AnalyzeInitialCsvRows = 0,
});

AsDataSet() configuration options

The AsDataSet() method accepts an optional configuration object to modify the behavior of the DataSet conversion:

var result = reader.AsDataSet(new ExcelDataSetConfiguration()
{
    // Gets or sets a value indicating whether to set the DataColumn.DataType 
    // property in a second pass.
    UseColumnDataType = true,

    // Gets or sets a callback to determine whether to include the current sheet
    // in the DataSet. Called once per sheet before ConfigureDataTable.
    FilterSheet = (tableReader, sheetIndex) => true,

    // Gets or sets a callback to obtain configuration options for a DataTable. 
    ConfigureDataTable = (tableReader) => new ExcelDataTableConfiguration()
    {
        // Gets or sets a value indicating the prefix of generated column names.
        EmptyColumnNamePrefix = "Column",

        // Gets or sets a value indicating whether to use a row from the 
        // data as column names.
        UseHeaderRow = false,

        // Gets or sets a callback to determine which row is the header row. 
        // Only called when UseHeaderRow = true.
        ReadHeaderRow = (rowReader) => {
            // F.ex skip the first row and use the 2nd row as column headers:
            rowReader.Read();
        },

        // Gets or sets a callback to determine whether to include the 
        // current row in the DataTable.
        FilterRow = (rowReader) => {
            return true;
        },

        // Gets or sets a callback to determine whether to include the specific
        // column in the DataTable. Called once per column after reading the 
        // headers.
        FilterColumn = (rowReader, columnIndex) => {
            return true;
        }
    }
});

Setting up AsDataSet() configuration, use the FilterRow callback to implement a «progress indicator» while loading, e.g.:

var result = reader.AsDataSet(new ExcelDataSetConfiguration()
{
    ConfigureDataTable = (tableReader) => new ExcelDataTableConfiguration()
    {
        FilterRow = (rowReader) => {
            int progress = (int)Math.Ceiling((decimal)rowReader.Depth / (decimal)rowReader.RowCount * (decimal)100);
            // progress is in the range 0..100
            return true;
        }
    }
});

Formatting

ExcelDataReader does not support formatting directly. Users may retreive the number format string for a cell through IExcelDataReader.GetNumberFormatString(i) and use the third party ExcelNumberFormat library for formatting purposes.

Example helper method using ExcelDataReader and ExcelNumberFormat to format a value:

string GetFormattedValue(IExcelDataReader reader, int columnIndex, CultureInfo culture)
{
    var value = reader.GetValue(columnIndex);
    var formatString = reader.GetNumberFormatString(columnIndex);
    if (formatString != null)
    {
        var format = new NumberFormat(formatString);
        return format.Format(value, culture);
    }
    return Convert.ToString(value, culture);
}

See also:

• https://github.com/andersnm/ExcelNumberFormat
• https://www.nuget.org/packages/ExcelNumberFormat

Important note when upgrading from ExcelDataReader 2.x

ExcelDataReader 3 had some breaking changes, and older code may produce error messages similar to:

'IExcelDataReader' does not contain a definition for 'AsDataSet'...
'IExcelDataReader' does not contain a definition for 'IsFirstRowAsColumnNames'...

To fix:

1. Make sure to rename any Excel namespace references in the code to the new namespace ExcelDataReader

2. Make sure the project has a reference to the ExcelDataReader.DataSet package to use AsDataSet()

3. Remove the line of code with IsFirstRowAsColumnNames and change the call to AsDataSet() to something like this:

var result = reader.AsDataSet(new ExcelDataSetConfiguration()
{
    ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
    {
        UseHeaderRow = true
    }
});

Important note on .NET Core

By default, ExcelDataReader throws a NotSupportedException «No data is available for encoding 1252.» on .NET Core and .NET 5.0 or later.

To fix, add a dependency to the package System.Text.Encoding.CodePages and then add code to register the code page provider during application initialization (f.ex in Startup.cs):

System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);

This is required to parse strings in binary BIFF2-5 Excel documents encoded with DOS-era code pages. These encodings are registered by default in the full .NET Framework, but not on .NET Core and .NET 5.0 or later.

C# Read Excel File with Examples

This tutorial explains how to read an Excel file in C#, as well as perform everyday tasks like data validation, database conversion, Web API intergrations, and formula modification. This article references code examples that utilize the IronXL .NET Excel library.

IronXL facilitates reading and editing Microsoft Excel documents with C#. IronXL neither requires Microsoft Excel nor does it require Interop. In fact, IronXL provides a faster and more intuitive API than Microsoft.Office.Interop.Excel.

IronXL Includes:

• Dedicated product support from our .NET engineers
• Easy installation via Microsoft Visual Studio
• 30 day free trial test for development. Licenses from $749.

Reading and creating Excel files in C# and VB.NET is easy using the IronXL software library.

Overview

Reading .XLS and .XLSX Excel Files Using IronXL

Below is a summary of the overal workflow for reading Excel files using IronXL:

1. Install the IronXL Excel Library. We can do this using our NuGet package or by downloading the .Net Excel DLL.
2. Use the WorkBook.Load method to read any XLS, XLSX or CSV document.
3. Get Cell values using intuitive syntax: sheet["A11"].DecimalValue

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-1.cs

using IronXL;
using System.Linq;
using System;

// Supported spreadsheet formats for reading include: XLSX, XLS, CSV and TSV
WorkBook workBook = WorkBook.Load("test.xlsx");
WorkSheet workSheet = workBook.WorkSheets.First();

// Select cells easily in Excel notation and return the calculated value
int cellValue = workSheet["A2"].IntValue;

// Read from Ranges of cells elegantly.
foreach (var cell in workSheet["A2:A10"])
{
    Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text);
}

// Advanced Operations
// Calculate aggregate values such as Min, Max and Sum
decimal sum = workSheet["A2:A10"].Sum();

// Linq compatible
decimal max = workSheet["A2:A10"].Max(c => c.DecimalValue);

Imports IronXL
Imports System.Linq
Imports System

' Supported spreadsheet formats for reading include: XLSX, XLS, CSV and TSV
Private workBook As WorkBook = WorkBook.Load("test.xlsx")
Private workSheet As WorkSheet = workBook.WorkSheets.First()

' Select cells easily in Excel notation and return the calculated value
Private cellValue As Integer = workSheet("A2").IntValue

' Read from Ranges of cells elegantly.
For Each cell In workSheet("A2:A10")
	Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text)
Next cell

' Advanced Operations
' Calculate aggregate values such as Min, Max and Sum
Dim sum As Decimal = workSheet("A2:A10").Sum()

' Linq compatible
Dim max As Decimal = workSheet("A2:A10").Max(Function(c) c.DecimalValue)

The code examples used in the next sections of this tutorial (along with the sample project code) will work on three sample Excel spreadsheets (see below for a visual):

Tutorial

1. Download the IronXL C# Library for FREE

Install-Package IronXL.Excel

The first thing we need to do is install the IronXL.Excel library, adding Excel functionality to the .NET framework.

Installing IronXL.Excel, is most easily achieved using our NuGet package, although you may also choose to manually install the DLL to your project or to your global assembly cache.

Installing the IronXL NuGet Package

1. In Visual Studio, right-click on the project select «Manage NuGet Packages …»

2. Search for the IronXL.Excel package and click on the Install button to add it to the project

   

Another way to install the IronXL library is using the NuGet Package Manager Console:

1. Enter the Package Manager Console

2. Type > Install-Package IronXL.Excel

   PM > Install-Package IronXL.Excel

Additionally, you can view the package on the NuGet website

Manual Installation

Alternatively, we can start by downloading the IronXL .NET Excel DLL and manually installing into Visual Studio.

2. Load an Excel Workbook

The WorkBook class represents an Excel sheet. To open an Excel File using C#, we use WorkBook.Load method, specifying the path of the Excel fil.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-2.cs

WorkBook workBook = WorkBook.Load(@"Spreadsheets\GDP.xlsx");

Dim workBook As WorkBook = WorkBook.Load("Spreadsheets\GDP.xlsx")

Sample: ExcelToDBProcessor

Each WorkBook can have multiple WorkSheet objects. Each one represents a single Excel worksheet in the Excel document. Use the WorkBook.GetWorkSheet method to retrieve a reference to a specific Excel worksheet.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-3.cs

Sample: ExcelToDB

Creating new Excel Documents

To create a new Excel document, construct a new WorkBook object with a valid file type.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-4.cs

WorkBook workBook = new WorkBook(ExcelFileFormat.XLSX);

Dim workBook As New WorkBook(ExcelFileFormat.XLSX)

Sample: ApiToExcelProcessor

Note: Use ExcelFileFormat.XLS toi support legacy versions of Microsoft Excel (95 and earlier).

Add a Worksheet to an Excel Document

As explained previously, an IronXL WorkBook contains a collection of one or more WorkSheets.

To create a new WorkSheet call WorkBook.CreateWorkSheet with the name of the worksheet.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-5.cs

WorkSheet workSheet = workBook.GetWorkSheet("GDPByCountry");

Dim workSheet As WorkSheet = workBook.GetWorkSheet("GDPByCountry")

3. Access Cell Values

Read and Edit a Single Cell

Access to the values of individual spreadsheet cells is carried out by retrieving the desired cell from its WorkSheet. as shown below:

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-16.cs

WorkBook workBook = WorkBook.Load("test.xlsx");
WorkSheet workSheet = workBook.DefaultWorksheet();
IronXL.Cell cell = workSheet["B1"];

Dim workBook As WorkBook = WorkBook.Load("test.xlsx")
Dim workSheet As WorkSheet = workBook.DefaultWorksheet()
Dim cell As IronXL.Cell = workSheet("B1")

IronXL’s Cell class represents an invidual cell in an Excel spreadsheet. It contains properties and methods that enable users to access and modify the cell’s value directly.

Each WorkSheet object manages an index of Cell objects corresponding to every cell value in an Excel worksheet. In the source code above, we reference the desired cell by its row and column index (cell B1 in this case) using standard array indexing syntax.

With a reference to Cell object, we can read and write data to and from a spreadsheet cell:

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-17.cs

IronXL.Cell cell = workSheet["B1"];
string value = cell.StringValue;   // Read the value of the cell as a string
Console.WriteLine(value);

cell.Value = "10.3289";           // Write a new value to the cell
console.WriteLine(cell.StringValue); 

Dim cell As IronXL.Cell = workSheet("B1")
Dim value As String = cell.StringValue ' Read the value of the cell as a string
Console.WriteLine(value)

cell.Value = "10.3289" ' Write a new value to the cell
console.WriteLine(cell.StringValue)

Read and Write a Range of Cell Values

The Range class represents a two-dimensional collection of Cell objects. This collection refers to a literal range of Excel cells. Obtain ranges by using the string indexer on a WorkSheet object.

The argument text is either the coordinate of a cell (e.g. «A1», as shown previously) or a span of cells from left to right top to bottom (e.g. «B2:E5»). It is also possible to call GetRange on a WorkSheet.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-6.cs

Range range = workSheet["D2:D101"];

Dim range As Range = workSheet("D2:D101")

Sample: DataValidation

There are several ways to read or edit the values of cells within a Range. If the count is known, use a For loop.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-7.cs

// Iterate through the rows
for (var y = 2; y <= 101; y++)
{
    var result = new PersonValidationResult { Row = y };
    results.Add(result);

    // Get all cells for the person
    var cells = workSheet[$"A{y}:E{y}"].ToList();

    // Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    // Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    // Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}

' Iterate through the rows
For y = 2 To 101
	Dim result = New PersonValidationResult With {.Row = y}
	results.Add(result)

	' Get all cells for the person
	Dim cells = workSheet($"A{y}:E{y}").ToList()

	' Validate the phone number (1 = B)
	Dim phoneNumber = cells(1).Value
	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, CStr(phoneNumber))

	' Validate the email address (3 = D)
	result.EmailErrorMessage = ValidateEmailAddress(CStr(cells(3).Value))

	' Get the raw date in the format of Month Day[suffix], Year (4 = E)
	Dim rawDate = CStr(cells(4).Value)
	result.DateErrorMessage = ValidateDate(rawDate)
Next y

Sample: DataValidation

Add Formula to a Spreadsheet

Set formula of Cells with the Formula property.

The code below iterates through each state and puts a percentage total in column C.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-13.cs

// Iterate through all rows with a value
for (var y = 2; y < i; y++)
{
    // Get the C cell
    Cell cell = workSheet[$"C{y}"].First();

    // Set the formula for the Percentage of Total column
    cell.Formula = $"=B{y}/B{i}";
}

' Iterate through all rows with a value
Dim y = 2
Do While y < i
	' Get the C cell
	Dim cell As Cell = workSheet($"C{y}").First()

	' Set the formula for the Percentage of Total column
	cell.Formula = $"=B{y}/B{i}"
	y += 1
Loop

Sample: AddFormulaeProcessor

Validate Spreadsheet Data

Use IronXL to validate a sheet of data. The DataValidation sample uses libphonenumber-csharp to validate phone numbers and uses standard C# APIs to validate email addresses and dates.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-8.cs

// Iterate through the rows
for (var i = 2; i <= 101; i++)
{
    var result = new PersonValidationResult { Row = i };
    results.Add(result);

    // Get all cells for the person
    var cells = worksheet[$"A{i}:E{i}"].ToList();

    // Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    // Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    // Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}

' Iterate through the rows
For i = 2 To 101
	Dim result = New PersonValidationResult With {.Row = i}
	results.Add(result)

	' Get all cells for the person
	Dim cells = worksheet($"A{i}:E{i}").ToList()

	' Validate the phone number (1 = B)
	Dim phoneNumber = cells(1).Value
	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, CStr(phoneNumber))

	' Validate the email address (3 = D)
	result.EmailErrorMessage = ValidateEmailAddress(CStr(cells(3).Value))

	' Get the raw date in the format of Month Day[suffix], Year (4 = E)
	Dim rawDate = CStr(cells(4).Value)
	result.DateErrorMessage = ValidateDate(rawDate)
Next i

The above code loops through each row in the spreadsheet and grabs the cells as a list. Each validates method checks the value of a cell and returns an error message if the value is invalid.

This code creates a new sheet, specifies headers, and outputs the error message results so that there is a log of invalid data.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-9.cs

var resultsSheet = workBook.CreateWorkSheet("Results");
resultsSheet["A1"].Value = "Row";
resultsSheet["B1"].Value = "Valid";
resultsSheet["C1"].Value = "Phone Error";
resultsSheet["D1"].Value = "Email Error";
resultsSheet["E1"].Value = "Date Error";
for (var i = 0; i < results.Count; i++)
{
    var result = results[i];
    resultsSheet[$"A{i + 2}"].Value = result.Row;
    resultsSheet[$"B{i + 2}"].Value = result.IsValid ? "Yes" : "No";
    resultsSheet[$"C{i + 2}"].Value = result.PhoneNumberErrorMessage;
    resultsSheet[$"D{i + 2}"].Value = result.EmailErrorMessage;
    resultsSheet[$"E{i + 2}"].Value = result.DateErrorMessage;
}
workBook.SaveAs(@"Spreadsheets\PeopleValidated.xlsx");

Dim resultsSheet = workBook.CreateWorkSheet("Results")
resultsSheet("A1").Value = "Row"
resultsSheet("B1").Value = "Valid"
resultsSheet("C1").Value = "Phone Error"
resultsSheet("D1").Value = "Email Error"
resultsSheet("E1").Value = "Date Error"
For i = 0 To results.Count - 1
	Dim result = results(i)
	resultsSheet($"A{i + 2}").Value = result.Row
	resultsSheet($"B{i + 2}").Value = If(result.IsValid, "Yes", "No")
	resultsSheet($"C{i + 2}").Value = result.PhoneNumberErrorMessage
	resultsSheet($"D{i + 2}").Value = result.EmailErrorMessage
	resultsSheet($"E{i + 2}").Value = result.DateErrorMessage
Next i
workBook.SaveAs("Spreadsheets\PeopleValidated.xlsx")

4. Export Data using Entity Framework

Use IronXL to export data to a database or convert an Excel spreadsheet to a database. The ExcelToDB sample reads a spreadsheet with GDP by country and then exports that data to an SQLite.

It uses EntityFramework to build the database and then export the data line by line.

Add the SQLite Entity Framework NuGet packages.

EntityFramework allows you to create a model object that can export data to the database.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-10.cs

public class Country
    {
        [Key]
        public Guid Key { get; set; }
        public string Name { get; set; }
        public decimal GDP { get; set; }
    }

Public Class Country
		<Key>
		Public Property Key() As Guid
		Public Property Name() As String
		Public Property GDP() As Decimal
End Class

To use a different database, install the corresponding NuGet package and find the equivalent of UseSqLite()

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-11.cs

public class CountryContext : DbContext
    {
        public DbSet<Country> Countries { get; set; }
        public CountryContext()
        {
            //TODO: Make async
            Database.EnsureCreated();
        }
        /// <summary>
        /// Configure context to use Sqlite
        /// </summary>
        /// <param name="optionsBuilder"></param>
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            var connection = new SqliteConnection($"Data Source=Country.db");
            connection.Open();
            var command = connection.CreateCommand();
            //Create the database if it doesn't already exist
            command.CommandText = $"PRAGMA foreign_keys = ON;";
            command.ExecuteNonQuery();
            optionsBuilder.UseSqlite(connection);
            base.OnConfiguring(optionsBuilder);
        }
    }

Public Class CountryContext
	Inherits DbContext

		Public Property Countries() As DbSet(Of Country)
		Public Sub New()
			'TODO: Make async
			Database.EnsureCreated()
		End Sub
		''' <summary>
		''' Configure context to use Sqlite
		''' </summary>
		''' <param name="optionsBuilder"></param>
		Protected Overrides Sub OnConfiguring(ByVal optionsBuilder As DbContextOptionsBuilder)
			Dim connection = New SqliteConnection($"Data Source=Country.db")
			connection.Open()
			Dim command = connection.CreateCommand()
			'Create the database if it doesn't already exist
			command.CommandText = $"PRAGMA foreign_keys = ON;"
			command.ExecuteNonQuery()
			optionsBuilder.UseSqlite(connection)
			MyBase.OnConfiguring(optionsBuilder)
		End Sub
End Class

Create a CountryContext, iterate through the range to create each record, and then SaveAsync to commit data to the database

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-12.cs

public async Task ProcessAsync()
{
    //Get the first worksheet
    var workbook = WorkBook.Load(@"Spreadsheets\GDP.xlsx");
    var worksheet = workbook.GetWorkSheet("GDPByCountry");
    //Create the database connection
    using (var countryContext = new CountryContext())
    {
        //Iterate through all the cells
        for (var i = 2; i <= 213; i++)
        {
            //Get the range from A-B
            var range = worksheet[$"A{i}:B{i}"].ToList();
            //Create a Country entity to be saved to the database
            var country = new Country
            {
                Name = (string)range[0].Value,
                GDP = (decimal)(double)range[1].Value
            };
            //Add the entity
            await countryContext.Countries.AddAsync(country);
        }
        //Commit changes to the database
        await countryContext.SaveChangesAsync();
    }
}

Public Async Function ProcessAsync() As Task
	'Get the first worksheet
	Dim workbook = WorkBook.Load("Spreadsheets\GDP.xlsx")
	Dim worksheet = workbook.GetWorkSheet("GDPByCountry")
	'Create the database connection
	Using countryContext As New CountryContext()
		'Iterate through all the cells
		For i = 2 To 213
			'Get the range from A-B
			Dim range = worksheet($"A{i}:B{i}").ToList()
			'Create a Country entity to be saved to the database
			Dim country As New Country With {
				.Name = CStr(range(0).Value),
				.GDP = CDec(CDbl(range(1).Value))
			}
			'Add the entity
			Await countryContext.Countries.AddAsync(country)
		Next i
		'Commit changes to the database
		Await countryContext.SaveChangesAsync()
	End Using
End Function

Sample: ExcelToDB

5. Download Data from an API to Spreadsheet

The following call makes a REST call with RestClient.Net. It downloads JSON and converts it into a «List» of the type RestCountry. It is then easy to iterate through each country and save the data from the REST API to an Excel spreadsheet.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-14.cs

var client = new Client(new Uri("https://restcountries.eu/rest/v2/"));
List<RestCountry> countries = await client.GetAsync<List<RestCountry>>();

Dim client As New Client(New Uri("https://restcountries.eu/rest/v2/"))
Dim countries As List(Of RestCountry) = Await client.GetAsync(Of List(Of RestCountry))()

Sample: ApiToExcel

This is what the API JSON data looks like.

The following code iterates through the countries and sets the Name, Population, Region, NumericCode, and Top 3 Languages in the spreadsheet.

:path=/static-assets/excel/content-code-examples/tutorials/how-to-read-excel-file-csharp-15.cs

for (var i = 2; i < countries.Count; i++)
{
    var country = countries[i];
    //Set the basic values
    workSheet[$"A{i}"].Value = country.name;
    workSheet[$"B{i}"].Value = country.population;
    workSheet[$"G{i}"].Value = country.region;
    workSheet[$"H{i}"].Value = country.numericCode;
    //Iterate through languages
    for (var x = 0; x < 3; x++)
    {
        if (x > (country.languages.Count - 1)) break;
        var language = country.languages[x];
        //Get the letter for the column
        var columnLetter = GetColumnLetter(4 + x);
        //Set the language name
        workSheet[$"{columnLetter}{i}"].Value = language.name;
    }
}

For i = 2 To countries.Count - 1
	Dim country = countries(i)
	'Set the basic values
	workSheet($"A{i}").Value = country.name
	workSheet($"B{i}").Value = country.population
	workSheet($"G{i}").Value = country.region
	workSheet($"H{i}").Value = country.numericCode
	'Iterate through languages
	For x = 0 To 2
		If x > (country.languages.Count - 1) Then
			Exit For
		End If
		Dim language = country.languages(x)
		'Get the letter for the column
		Dim columnLetter = GetColumnLetter(4 + x)
		'Set the language name
		workSheet($"{columnLetter}{i}").Value = language.name
	Next x
Next i

Object Reference and Resources

You may also find the IronXL class documentation within the Object Reference of great value.

In addition, there are other tutorials which may shed light in other aspects of IronXL.Excel including Creating, Opening, Writing, Editing, Saving and Exporting XLS, XLSX and CSV files without using Excel Interop.

Summary

IronXL.Excel is alone .NET software library for reading a wide variety of spreadsheet formats. It does not require Microsoft Excel to be installed, and is not dependant on Interop.

Tutorial Quick Access