title: DataTable Union
body: <p>Could you please check the following what is wrong in this.</p>
  
  <p>I need union of this but it returns 6 record instead of 5(because "Amir" occurs two times)</p>
  
  <pre><code>DataTable dt1 = new DataTable();
  dt1.Columns.Add(new DataColumn("Name"));
  dt1.Rows.Add(dt1.NewRow()["Name"] = "Imran");
  dt1.Rows.Add(dt1.NewRow()["Name"] = "Amir");
  dt1.Rows.Add(dt1.NewRow()["Name"] = "Asif");
  
  DataTable dt2 = new DataTable();
  dt2.Columns.Add(new DataColumn("Name"));
  dt2.Rows.Add(dt2.NewRow()["Name"] = "Tandulkar");
  dt2.Rows.Add(dt2.NewRow()["Name"] = "Amir");
  dt2.Rows.Add(dt2.NewRow()["Name"] = "Sheqwag");
  
   DataTable dtUnion = dt1.AsEnumerable()
    .Union(dt2.AsEnumerable()).CopyToDataTable&lt;DataRow&gt;();
  </code></pre>