C#: DataTable to CSV

Recently I wrote a small program to allow me to connect to a SQL database and export a selected table to a CSV file. So I needed a method that can take in a DataTable and the delimiter character to use. The returned result is a string which can be save straight to a text file.

Below is the method in my program, you may copy, modify and use it in your own program.

I use a StringBuilder class to build my lines of comma separated values and then return it as a String type. Currently the code only format string values with double quotes inserted around the value and the rest is a straight output.

private string ToDelimited(DataTable table, string delimiter)
{
    StringBuilder strBuilder = new StringBuilder();
    string line = string.Empty;
    
    foreach (DataColumn col in table.Columns)
    {
        line += col.ColumnName;
        if (table.Columns.IndexOf(col) + 1 < table.Columns.Count)
        {
            line += ",";
        }
    }
    
    strBuilder.AppendLine(line);

    foreach (DataRow row in table.Rows)
    {
        line = string.Join(delimiter, Array.ConvertAll<object, string>
            (row.ItemArray, delegate(object obj)
        {
            if (obj is string)
            {
                return string.Format("\"{0}\"", obj as string);
            }
            else
            {
                return obj.ToString();
            }
        }));
        strBuilder.AppendLine(line);
    }
    return strBuilder.ToString();
}