Get all files not present int a datatable

Question

I have a MySQL table with a list of file name. I would like to get a list of all file in a directory only if their names are not present in the table.

I can put the list of the database's file in a Datatable and write something like:

 string[] files = Directory.GetFiles(directory);
 foreach (Datarow row in dataTable.Rows)
   for (int i=0; i<files.Length; i++)
      if (row[0].equals(files[i]) {
          files[i].delete();
          break;
       }

The upper code is only a pseudo-example. Can't I directly use Directory.GetFiles(directory) by specifying a filter in order to don't write all the iteraction?

Answer 1

please find code snippet below

decided to do it in steps - to have more maintainable code

void Main()
{
    // given a list of files from db
    DataTable dataTable = new DataTable("x");  
    dataTable.Columns.Add("file", typeof(string));  
    dataTable.Rows.Add("HaxLogs.txt");dataTable.Rows.Add("swapfile.sys");dataTable.Rows.Add("four.txt");
    var directory = "c:\\";
    var directoryFilesWithPaths = Directory.GetFiles(directory)
            .Select( x=> new FileEntry { Path = x, FileName = Path.GetFileName(x)});

            var directoryFiles = directoryFilesWithPaths.Select(x => x.FileName).ToList();
            var filesList = (from DataRow dr in dataTable.Rows
                            select dr[0].ToString()).ToList();

            var filesToProcess = directoryFiles.Except(filesList);
        foreach (var file in filesToProcess)
        {
            // process file here

            Console.WriteLine(file);
        }

}