title: Duplicates in data table should be skipped
body: <p>Here the below is the input text file. I am accessing it through data table as shown in the below code. </p>
  
  <p>Input file has the following data:</p>
  
  <pre><code>ABC
  D
  E
  F
  1234
  2345
  2345
  BAC
  A
  B
  C
  2345
  ABC
  D
  E
  F
  12345
  </code></pre>
  
  <p>I would like to get the following output :</p>
  
  <pre><code>ABC
  D
  E
  F
  1234
  2345
  2345
  12345
  BAC
  A
  B
  C
  2345
  </code></pre>
  
  <p>Here is the code which I am trying to execute to get the above output through data table or data set.</p>
  
  <pre><code>class Program
  {
      private string dirCSV = @"C:\Prod.txt";
      // load the file in the data in the data set
      public DataSet loadCVS()
      {
          DataSet ds = new DataSet();
          try
          {
  
              string connString = string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=Text;", Path.GetDirectoryName(dirCSV));
              OleDbConnection conn = new OleDbConnection(connString);
              conn.Open();
              OleDbDataAdapter DA = new OleDbDataAdapter("SELECT * FROM Prod.txt", conn);
              DataTable DT = new DataTable();
              DA.Fill(DT);
              DT.DefaultView.Sort = "Item/Variant ASC";
              conn.Close();
          }     
          catch (Exception e){ /*Error*/}
  
          return ds;
      }
  }
  </code></pre>
  
  <p>Here it will be used:</p>
  
  <pre><code>static void Main(string[] args)
  {
      Program obj = new Program();
      obj.loadCVS();
  }
  </code></pre>
  
  <p>However I got the data in data table but I am unable to sort the date as shown in the  output in above format.</p>
  
  <p>Can you please help in this? Any ideas?</p>