Validate content of csv file c#

Question

I have a requirement where user will be uploading a csv file in the below format which will contain around 1.8 to 2 million records

SITE_ID,HOUSE,STREET,CITY         


        

Answer 1

I would suggest to using a CSV-library to read the file.
For example you can use LumenWorksCsvReader: https://www.nuget.org/packages/LumenWorksCsvReader

Your approach with an regex validation is actually ok. For example, you could create a "Validation Dictionary" and check every CSV Value against the regex-expression.

Then you can build a function that can validate a CSV-File with such a "Validation Dictionary".

See here:

string lsInput = @"SITE_ID,HOUSE,STREET,CITY,STATE,ZIP,APARTMENT
44,545395,PORT ROYAL,CORPUS CHRISTI,TX,78418,2
44,608646,TEXAS AVE,ODESSA,TX,79762,
44,487460,EVERHART RD,CORPUS CHRISTI,TX,78413,
44,275543,EDWARD GARY,SAN MARCOS,TX,78666,4
44,136811,MAGNOLIA AVE,SAN ANTONIO,TX,78212";

Dictionary loValidations = new Dictionary();
loValidations.Add("SITE_ID", @"^\d+$"); //it can only be an integer and it is required.
//....

bool lbValid = true;
using (CsvReader loCsvReader = new CsvReader(new StringReader(lsInput), true, ','))
{
    while (loCsvReader.ReadNextRecord())
    {
        foreach (var loValidationEntry in loValidations)
        {
            if (!Regex.IsMatch(loCsvReader[loValidationEntry.Key], loValidationEntry.Value))
            {
                lbValid = false;
                break;
            }
        }
        if (!lbValid)
            break;
    }
}
Console.WriteLine($"Valid: {lbValid}");