title: DataView RowFilter doesn't filter the Rows on DataGridView
body: <p>I have this function <code>button_Search1_Click</code> to search for comments that match keywords, then display these flagged comments in <code>dataGridView_flaggedComments</code>.</p>
  
  <p>Next, if there's any changes on the <code>comboBox_stockIndex</code>, I want the filter to take place i.e. filter the flagged comments in <code>dataGridView_flaggedComments</code> with the <code>Tickers_Ticker_ID</code> of <code>1</code>. But when I do that, all the comments (regardless flagged or not) belong to <code>Tickers_Ticker_ID</code> of <code>1</code> display on my <code>dataGridView_flaggedComments</code>. It should have only display the flagged comments for <code>Tickers_Ticker_ID</code> of <code>1</code>, not all the comments.</p>
  
  <p>I think there's something wrong with the <code>DataSource</code> but I couldn't figure it out. Any help would be very very much appreciated! Thank you!</p>
  
  <p>(If I did miss any similar questions, kindly point it out. Thank you very much!)</p>
  
  <pre><code>private void button_Search1_Click(object sender, EventArgs e)
  {
      commentCount = 0;
      richTextBox_flaggedComments.Clear();
      dataGridView_flaggedComments.Refresh();
      DataTable flaggedcomments = new DataTable("flaggedcomments");
      using (MySqlConnection sqlConn = new MySqlConnection(strProvider))
      {
          using (MySqlDataAdapter da = new MySqlDataAdapter(
          "SELECT Comment_ID, Comments_Date, Author, Title, Comments_Comment, " + 
                " Tickers_Ticker_ID FROM comments ORDER BY Comments_Date ASC", sqlConn))
          {
              da.Fill(flaggedcomments);
          }
      }
      StringBuilder sb = new StringBuilder();
      string[] words = File.ReadAllLines(sourceDirTemp + 
                            comboBox_crimeKeywords.SelectedItem.ToString() + ".txt");
      var query = flaggedcomments.AsEnumerable().Where(r =&gt;
          words.Any(wordOrPhrase =&gt; Regex.IsMatch(r.Field&lt;string&gt;("Comments_Comment"),
                @"\b" + Regex.Escape(wordOrPhrase) + @"\b",  RegexOptions.IgnoreCase)));
  
      dataGridView_flaggedComments.DataSource = query.AsDataView();
  }
  
  
  private void comboBox_stockIndex_SelectedIndexChanged(object sender, EventArgs e)
  {
      DataView dv = dataGridView_flaggedComments.DataSource as DataView;
      if (dv == null)
          throw new Exception("Bad Data Source type");
      else
      {
          dv.RowFilter = string.Format("Tickers_Ticker_ID = '1'");
          dataGridView_flaggedComments.DataSource = dv;
      }
  }
  </code></pre>