new records added in csv

Question

Hi, I need help on how to update to the database if there are new records added in CSV file.

 

If only 3 new records added in the CSV file, only insert those 3 new records, not all records.

if (LWT > 0)
{
    Console.WriteLine("There are no changes in lastWriteTime CSV file");
}
else
{
    Console.WriteLine("There are changes lastWriteTime in CSV file");
    var lf2 = "insert into
    listfile(filename,lastwritetime)values(@filename,@lastwritetime)";
    var cmd3 = new NpgsqlCommand(lf2, conn);
    cmd3.Parameters.AddWithValue("filename", Convert.ToString(file));
    string filename = cmd3.Parameters["@filename"].Value.ToString();
    Console.WriteLine("Record inserted successfully. filename = " + file);
}