title: how to remove data from a dataset table where is relation
body: <p>I have a dataset with two tables and between these tables there is a relation:</p>
  
  <pre><code> DataColumn dc1;
          DataColumn dc2;
  
          dc1 = q.Tables[0].Columns["dateFrom"];
          dc2 = q.Tables[1].Columns["dateFrom"];
          DataRelation dr = new DataRelation("tracker", dc1, dc2, false);
  </code></pre>
  
  <p>Now I want to remove from the first table all the rows that don't have a data in the second table. How can I do that?</p>