Multiple form_open with button - forms

Question

I have several buttons which should make different things.
To one, a button should make one entry in table 1 and another in table 2.
But if I do it as in the code below.
He always makes an entry in Table 1.
How can I assign the respective buttons?
<?php echo form_open('Karte/insert_artikel'); ?>
<?php echo form_open('Karte/insert_trade'); ?>
<input type="hidden" name="add_karte_id" value="<?php echo $edition_views['tb_karte_id']; ?>">
<input type="hidden" name="add_karten_stats_id" value="<?php echo $edition_views['tb_karte_karten_stats']; ?>">
<input type="hidden" name="add_karte_sprache" value="<?php echo $edition_views['tb_sprache_id']; ?>">
<input type="hidden" name="add_karte_qualitat" value="<?php echo $edition_views['tb_qualitat_id']; ?>">
<input type="hidden" name="add_karte_auflage" value="<?php echo $edition_views['tb_auflage_id']; ?>">
<input type="hidden" name="add_karte_edition_stats" value="<?php echo $edition_views['tb_karte_edition_stats']; ?>">
<input type="hidden" name="add_karte_datum" value="<?php $date = date_create($edition_views['tb_karte_datum']); echo date_format($date,"Y-m-d H:i:s");?>">
<tr>
<td><?php echo $edition_views['tb_edition_kurzel']; ?>-<?php echo $edition_views['tb_sprache_kurzel']; ?><?php echo $edition_views['tb_edition_stats_nummer']; ?></td>
<td><button class="btn btn-default" data-toggle="tooltip" data-placement="top" title="<?php echo $edition_views['tb_qualitat_name']; ?>"><img src="<?php echo base_url(); ?>assets/images/site/qualitat/<?php echo $edition_views['tb_qualitat_id']; ?>.png"/> <?php echo $edition_views['tb_qualitat_short']; ?></button></td>
<td><button class="btn btn-default" data-toggle="tooltip" data-placement="top" title="<?php echo $edition_views['tb_rare_name']; ?>"><?php echo $edition_views['tb_rare_short']; ?></button></td>
<td><?php echo $edition_views['tb_auflage_name_de']; ?></td>
<td><?php $date = date_create($edition_views['tb_karte_datum']); echo date_format($date,"d.m.Y");?></td>
<td><?php echo str_pad($edition_views['tb_karte_anzahl'], 2, '0', STR_PAD_LEFT); ?></td>
<td>
<?php
switch($edition_views['tb_karte_versuche'])
{
case (0):
echo "<FONT COLOR='#000000'>".$edition_views['tb_karte_versuche']."</FONT>";
break;
case (1):
echo "<strong><FONT COLOR='#D7DF01'>".$edition_views['tb_karte_versuche']."</FONT></strong>";
break;
case (2):
echo "<strong><FONT COLOR='#298A08'>".$edition_views['tb_karte_versuche']."</FONT></strong>";
break;
case (3):
echo "<strong><FONT COLOR='#DF0101'>".$edition_views['tb_karte_versuche']."</FONT></strong>";
break;
}
?>
</td>
<td>
<div class="input-group">
<span class="input-group-btn">
<button type="button" class="btn btn-default btn-number" disabled="disabled" data-type="minus" data-field="add_karte_menge[<?php echo $edition_views['tb_karte_id']; ?>]"><span class="glyphicon glyphicon-minus"></span></button>
</span>
<input type="text" name="add_karte_menge[<?php echo $edition_views['tb_karte_id']; ?>]" class="form-control input-number" value="1" min="1" max="<?php echo $edition_views['tb_karte_anzahl']; ?>">
<span class="input-group-btn">
<button type="button" class="btn btn-default btn-number" data-type="plus" data-field="add_karte_menge[<?php echo $edition_views['tb_karte_id']; ?>]"><span class="glyphicon glyphicon-plus"></span></button>
<button type="submit" class="btn btn-default" data-toggle="tooltip" data-placement="top" title="Verkauf Hinzufügen"><span class="glyphicon glyphicon-shopping-cart" aria-hidden="true"></span></button>
<button type="submit" class="btn btn-default" data-toggle="tooltip" data-placement="top" title="Tausch Hinzufügen"><span class="glyphicon glyphicon-transfer" aria-hidden="true"></span></button>
<button type="submit" class="btn btn-default" data-toggle="tooltip" data-placement="top" title="Zur Sammlung"><span class="glyphicon glyphicon-gift" aria-hidden="true"></span></button>
<button type="submit" class="btn btn-default" data-toggle="tooltip" data-placement="top" title="Bearbeiten"><span class="glyphicon glyphicon-pencil" aria-hidden="true"></span></button>
<button type="submit" class="btn btn-default" data-toggle="tooltip" data-placement="top" title="Verloren"><span class="glyphicon glyphicon-question-sign" aria-hidden="true"></span></button>
</span>
</div>
</td>
</tr>
<?php echo form_close(); ?>
<?php echo form_close(); ?>

Answer 1

You cannot nest forms.
You have a couple of options here:
A) Have separate forms (not nested) with a button in each form. Each form would be directed to its own controller which redirects back to the same controller or view afterwards
B) Have a single form and a single controller, but attach a different name to each button - i.e.
<form action="/some-controller" method="post">
<button name="do_something" value="1">Do Something</button>
<button name="do_something_different" value="1">Do Something Different</button>
</form>
Then in your controller you can look for the posted variables do_something and do_something_different to determine which button the user clicked and determine your action accordingly.