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c#asp.netasp.net-mvccsvcsvhelper

Using CsvHelper, How to map to a second column, if the value of the first column equals 0

Is there a way to map to a second field, if the first field is less than 0?

For example, if you are mapping a csv file with columns foo and bar:

Map(m => m.Price).Name("foo");

And if the column foo equals 0, can we then map Price to the value of the bar column instead.

Solution

  • You have to manually convert the column like below.

    Map(x => x.Price)
    .Name("foo")
    .ConvertUsing(row =>
    {
        var fooValue = row.GetField<decimal>("foo");

        if (fooValue == 0m)
        {
            return row.GetField<decimal>("bar");
        }
        return fooValue;
    });

    That said, I don't think you should be using CsvHelper to do conditional mapping. Ideally, you'd have a mapping for your CSV model and another model you want to map to. Then have code that maps your CSV model to that other model.