DataTableExtensionWriteCsv(DataTable, String, Char, IFormatProvider, Encoding, IEnumerableString, String) Method

Writes the content of the DataTable as a CSV file with header.

Definition

Namespace: FolkerKinzel.CsvTools
Assembly: FolkerKinzel.CsvTools (in FolkerKinzel.CsvTools.dll) Version: 2.0.1+2345335399184346d9b2cc992ed5c814406052c1

C#

public static void WriteCsv(
	this DataTable dataTable,
	string filePath,
	char delimiter = ',',
	IFormatProvider? formatProvider = null,
	Encoding? textEncoding = null,
	IEnumerable<string>? csvColumnNames = null,
	string? format = null
)

VB

<ExtensionAttribute>
Public Shared Sub WriteCsv ( 
	dataTable As DataTable,
	filePath As String,
	Optional delimiter As Char = ","C,
	Optional formatProvider As IFormatProvider = Nothing,
	Optional textEncoding As Encoding = Nothing,
	Optional csvColumnNames As IEnumerable(Of String) = Nothing,
	Optional format As String = Nothing
)

C++

public:
[ExtensionAttribute]
static void WriteCsv(
	DataTable^ dataTable, 
	String^ filePath, 
	wchar_t delimiter = L',', 
	IFormatProvider^ formatProvider = nullptr, 
	Encoding^ textEncoding = nullptr, 
	IEnumerable<String^>^ csvColumnNames = nullptr, 
	String^ format = nullptr
)

F#

[<ExtensionAttribute>]
static member WriteCsv : 
        dataTable : DataTable * 
        filePath : string * 
        ?delimiter : char * 
        ?formatProvider : IFormatProvider * 
        ?textEncoding : Encoding * 
        ?csvColumnNames : IEnumerable<string> * 
        ?format : string 
(* Defaults:
        let _delimiter = defaultArg delimiter ','
        let _formatProvider = defaultArg formatProvider null
        let _textEncoding = defaultArg textEncoding null
        let _csvColumnNames = defaultArg csvColumnNames null
        let _format = defaultArg format null
*)
-> unit

Parameters

dataTable DataTable

The DataTable to save.

filePath String

The file path of the CSV file to be written.

delimiter Char (Optional)

The field separator character.

formatProvider IFormatProvider (Optional)

The provider to use to format the value.

- or -

A null reference for InvariantCulture.

textEncoding Encoding (Optional)

The Encoding to be used or null for UTF8.

csvColumnNames IEnumerableString (Optional)

A collection of ColumnNames from dataTable that allows to select the DataColumns to export and to determine their order in the CSV file, or null to save the whole DataTable using its current column order.

Each item in this collection MUST be a ColumnName in dataTable.

format String (Optional)

A format String to use for all items that implement IFormattable.

- or -

A null reference to use the default format for each item.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type DataTable. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

Creates a new CSV file. If the target file already exists, it is truncated and overwritten.

For serialization ToString(String, IFormatProvider) is used if the item implements IFormattable, otherwise ToString.

When exchanging CSV data with Excel, the appropriate arguments can be determined with GetExcelArguments.

Example

Note

In the following code examples - for easier readability - exception handling has been omitted.

Simple DataTable serialization with CSV:

C#

using System.Data;
using System.Globalization;
using System.Text;
using FolkerKinzel.CsvTools;

namespace Examples;

internal static class DataTableExample
{
    internal static void SerializingDataTablesAsCsv(string filePath)
    {
        using var table = new DataTable();
        _ = table.Columns.Add("id", typeof(int));
        _ = table.Columns.Add("name", typeof(string));
        _ = table.Columns.Add("sales", typeof(decimal));
        _ = table.Columns.Add("last_purchase", typeof(DateOnly));
        _ = table.Columns.Add("reserved", typeof(string));

        _ = table.Rows.Add(1, "Susi", 4_711m, new DateOnly(2004, 3, 14), "my comment");
        _ = table.Rows.Add(2, "Tom", 38_527.28m, new DateOnly(2006, 12, 24));
        _ = table.Rows.Add(3, "Sören", 25.8m, new DateOnly(2011, 8, 27));

        string[] csvColumns = ["name", "last_purchase", "sales"];
        table.WriteCsv(filePath, csvColumnNames: csvColumns);

        Console.WriteLine(File.ReadAllText(filePath));


        // Write a CSV file that can be imported by Excel:
        Console.WriteLine();
        Console.WriteLine("Current culture: {0}", CultureInfo.CurrentCulture);
        Console.WriteLine();

        (char delimiter,
         IFormatProvider formatProvider,
         Encoding encoding) = Csv.GetExcelArguments();
        table.WriteCsv(filePath, delimiter, formatProvider, encoding, csvColumns);

        Console.WriteLine(File.ReadAllText(filePath, encoding));
    }
}

/*
Console output:

name,last_purchase,sales
Susi,03/14/2004,4711
Tom,12/24/2006,38527.28
Sören,08/27/2011,25.8

Current culture: de-DE

name;last_purchase;sales
Susi;14.03.2004;4711
Tom;24.12.2006;38527,28
Sören;27.08.2011;25,8
*/

Exceptions

ArgumentNullException	dataTable or filePath is null.
ArgumentException	filePath is not a valid file path. - or - csvColumnNames contains an item that is not a ColumnName in dataTable.
ArgumentOutOfRangeException	delimiter is either the double quotes " or a line break character ('\r' or '\n').
IOException	I/O error.