How to solve problem with CSV Mapping using CsvHelper

Question

I have a CSV File with multiple fields(check below for format)

ArticleNumber;Shop1;Shop2;Shop3;Shop4;Shop5;Shop6;Shop7
123455;50;51;52;53;54;55;56

In fields Shop1,Shop2....Shop7 I have product Prices. I receive file like this, so I need to find a cool way to solve my problem. I want to read this CSV using CsvHelper library, but I don't know how to map fields. As a result I want something like this:

ArticleNumber	Shop	Price
123455	Shop1	50
123455	Shop2	51
123455	Shop3	52
123455	Shop4	53
123455	Shop5	54
123455	Shop6	55

Answer 1

I think this will get you the format you are looking for.

void Main()
{
    var config = new CsvConfiguration(CultureInfo.InvariantCulture)
    {
        Delimiter = ";"
    };
    
    using (var reader = new StringReader("ArticleNumber;Shop1;Shop2;Shop3;Shop4;Shop5;Shop6;Shop7\n123455;50;51;52;53;54;55;56\n123456;60;61;62;63;64;65;66"))
    using (var csv = new CsvReader(reader, config))
    {
        csv.Context.RegisterClassMap<ArticleMap>();
        
        csv.Read();
        csv.ReadHeader();
        
        var shops = csv.HeaderRecord.Skip(1).ToArray();
        
        var records = csv.GetRecords<Article>().ToList();

        var results = records.SelectMany(r => r.Shop
                                .Select((s, i) => new ArticleShop 
                                                    { 
                                                        ArticleNumber = r.ArticleNumber, 
                                                        Shop = shops[i], 
                                                        Price = s
                                                    })
                                ).ToList();
    }   
}

public class ArticleMap : ClassMap<Article>
{
    public ArticleMap()
    {
        Map(x => x.ArticleNumber);
        Map(x => x.Shop).Index(1);
    }
}

public class Article
{
    public int ArticleNumber { get; set; }
    public List<double> Shop { get; set; }
}

public class ArticleShop
{
    public int ArticleNumber { get; set; }
    public string Shop { get; set; }
    public double Price { get; set; }
}