Parsing CSV files in C#, with header

Question

Is there a default/official/recommended way to parse CSV files in C#? I don\'t want to roll my own parser.

Also, I\'ve seen instances of people using ODBC/OLE DB to

Answer 1

In a business application, i use the Open Source project on codeproject.com, CSVReader.

It works well, and has good performance. There is some benchmarking on the link i provided.

A simple example, copied from the project page:

using (CsvReader csv = new CsvReader(new StreamReader("data.csv"), true))
{
    int fieldCount = csv.FieldCount;
    string[] headers = csv.GetFieldHeaders();

    while (csv.ReadNextRecord())
    {
        for (int i = 0; i < fieldCount; i++)
            Console.Write(string.Format("{0} = {1};", headers[i], csv[i]));

        Console.WriteLine();
    }
}

As you can see, it's very easy to work with.

Answer 2

I have written TinyCsvParser for .NET, which is one of the fastest .NET parsers around and highly configurable to parse almost any CSV format.

It is released under MIT License:

• https://github.com/bytefish/TinyCsvParser

You can use NuGet to install it. Run the following command in the Package Manager Console.

PM> Install-Package TinyCsvParser

Usage

Imagine we have list of Persons in a CSV file persons.csv with their first name, last name and birthdate.

FirstName;LastName;BirthDate
Philipp;Wagner;1986/05/12
Max;Musterman;2014/01/02

The corresponding domain model in our system might look like this.

private class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public DateTime BirthDate { get; set; }
}

When using TinyCsvParser you have to define the mapping between the columns in the CSV data and the property in you domain model.

private class CsvPersonMapping : CsvMapping<Person>
{

    public CsvPersonMapping()
        : base()
    {
        MapProperty(0, x => x.FirstName);
        MapProperty(1, x => x.LastName);
        MapProperty(2, x => x.BirthDate);
    }
}

And then we can use the mapping to parse the CSV data with a CsvParser.

namespace TinyCsvParser.Test
{
    [TestFixture]
    public class TinyCsvParserTest
    {
        [Test]
        public void TinyCsvTest()
        {
            CsvParserOptions csvParserOptions = new CsvParserOptions(true, new[] { ';' });
            CsvPersonMapping csvMapper = new CsvPersonMapping();
            CsvParser<Person> csvParser = new CsvParser<Person>(csvParserOptions, csvMapper);

            var result = csvParser
                .ReadFromFile(@"persons.csv", Encoding.ASCII)
                .ToList();

            Assert.AreEqual(2, result.Count);

            Assert.IsTrue(result.All(x => x.IsValid));

            Assert.AreEqual("Philipp", result[0].Result.FirstName);
            Assert.AreEqual("Wagner", result[0].Result.LastName);

            Assert.AreEqual(1986, result[0].Result.BirthDate.Year);
            Assert.AreEqual(5, result[0].Result.BirthDate.Month);
            Assert.AreEqual(12, result[0].Result.BirthDate.Day);

            Assert.AreEqual("Max", result[1].Result.FirstName);
            Assert.AreEqual("Mustermann", result[1].Result.LastName);

            Assert.AreEqual(2014, result[1].Result.BirthDate.Year);
            Assert.AreEqual(1, result[1].Result.BirthDate.Month);
            Assert.AreEqual(1, result[1].Result.BirthDate.Day);
        }
    }
}

User Guide

A full User Guide is available at:

• http://bytefish.github.io/TinyCsvParser/

Answer 3

Here is a short and simple solution.

                using (TextFieldParser parser = new TextFieldParser(outputLocation))
                 {
                        parser.TextFieldType = FieldType.Delimited;
                        parser.SetDelimiters(",");
                        string[] headers = parser.ReadLine().Split(',');
                        foreach (string header in headers)
                        {
                            dataTable.Columns.Add(header);
                        }
                        while (!parser.EndOfData)
                        {
                            string[] fields = parser.ReadFields();
                            dataTable.Rows.Add(fields);
                        }
                    }

Answer 4

Let a library handle all the nitty-gritty details for you! :-)

Check out FileHelpers and stay DRY - Don't Repeat Yourself - no need to re-invent the wheel a gazillionth time....

You basically just need to define that shape of your data - the fields in your individual line in the CSV - by means of a public class (and so well-thought out attributes like default values, replacements for NULL values and so forth), point the FileHelpers engine at a file, and bingo - you get back all the entries from that file. One simple operation - great performance!

Answer 5

If you need only reading csv files then I recommend this library: A Fast CSV Reader
If you also need to generate csv files then use this one: FileHelpers

Both of them are free and opensource.

Answer 6

Some time ago I had wrote simple class for CSV read/write based on Microsoft.VisualBasic library. Using this simple class you will be able to work with CSV like with 2 dimensions array. You can find my class by the following link: https://github.com/ukushu/DataExporter

Simple example of usage:

Csv csv = new Csv("\t");//delimiter symbol

csv.FileOpen("c:\\file1.csv");

var row1Cell6Value = csv.Rows[0][5];

csv.AddRow("asdf","asdffffff","5")

csv.FileSave("c:\\file2.csv");

For reading header only you need is to read csv.Rows[0] cells :)