title: Delete All row from DataTable in DataSet
body: <p>I'd like to erase all row in a datatable located in a dataset and then update the DataBase using the method <code>Update()</code> of <code>TableAdapter</code>. </p>
  
  <p>The insert works fine, I put it so you can see what I'm doing. I tried the method <code>Clear()</code> for datatable which was supposed to erase all row but at the moment it does nothing. </p>
  
  <p>I would like to use a kind of SQL query like <code>DELETE * FROM demande;</code> but I dont get how to do it</p>
  
  <pre><code>protected void InsertDemande_Click(object sender, EventArgs e)
  {
      //TB = textBox
      //Parsing date (5th row of my dataTable is type date)
      string[] tabdate = TB_date_demande.Text.Split('/');
      DateTime date = new DateTime(int.Parse(tabdate[2]), int.Parse(tabdate[1]), int.Parse(tabdate[0]));
  
      //In my dataset "Demande", on my table "Demande", i add a new row type "demande" with all good parameters
      ds_Demande.Demande.AddDemandeRow(TB_demande_ID.Text, TB_user_ID.Text, TB_nom_fichier.Text, int.Parse(TB_poids_fichier.Text), date);
  
  
      ta_Demande.Update(ds_Demande);//update the database
      LabelResponse.Text = "Ajout effectué avec succès";
      GridViewDemande.DataBind();//refresh gridview
  }
  
  protected void ClearTable_Click(object sender, EventArgs e)
  {
      ds_Demande.Demande.Clear();//doesn't seem to do anything
      ta_Demande.Update(ds_Demande);
      GridViewDemande.DataBind();
  }
  </code></pre>