Reading/writing CSV/tab delimited files in c#

Question

I need to read from a CSV/Tab delimited file and write to such a file as well from .net.

The difficulty is that I don't know the structure of each file and need to write the cvs/tab file to a datatable, which the FileHelpers library doesn't seem to support.

I've already written it for Excel using OLEDB, but can't really see a way to write a tab file for this, so will go back to a library.

Can anyone help with suggestions?

Answer 1

Here are a couple CSV reader implementations:

http://www.codeproject.com/KB/database/CsvReader.aspx

http://www.heikniemi.fi/jhlib/ (just one part of the library; includes a CSV writer too)

I doubt there is a standard way to convert CSV to DataTable or database 'automatically', you'll have to write code to do that. How to do that is a separate question.

Answer 2

I used this CsvReader, it is really great and well configurable. It behaves well with all kinds of escaping for strings and separators. The escaping in other quick and dirty implementations were poor, but this lib is really great at reading. With a few additional codelines you can also add a cache if you need to.

Writing is not supported but it rather trivial to implement yourself. Or inspire yourself from this code.

Answer 3

You'll create your datatable in code, and (presuming a header row) can create columns based on your first line in the file. After that, it will simply be a matter of reading the file and creating new rows based on the data therein.

You could use something like this:

DataTable Tbl = new DataTable();
using(StreamReader sr = new StreamReader(path))
{
  int count = 0;
  string headerRow = sr.Read();
  string[] headers = headerRow.split("\t") //Or ","
  foreach(string h in headers)
  {
    DataColumn dc = new DataColumn(h);
    Tbl.Columns.Add(dc);
    count++;
  }
  while(sr.Peek())
  {
    string data = sr.Read();
    string[] cells = data.Split("\t") 
    DataRow row = new DataRow();
    foreach(string c in cells)
    {
      row.Columns.Add(c);
    }
    Tbl.Rows.Add(row);
  }
}

The above code has not been compiled, so it may have some errors, but it should get you on the right track.

Answer 4

I hope this following link will help you, please try this

This Contain Sample Code for how to read the Data from the Tab of Excel

http://www.codeproject.com/KB/office/excel_using_oledb.aspx

Answer 5

.NET comes with a CSV/tab delminited file parser called the TextFieldParser class.

http://msdn.microsoft.com/en-us/library/microsoft.visualbasic.fileio.textfieldparser.aspx

It supports the full RFC for CSV files and really good error reporting.