Join 2 tables by merk_id - php

Question

I'm trying to combine to tables. I got 11 different brands and I got wheels that belong to a brand. You can select a brand by its name with an option selectbox and when submut I want alle the wheels with that brand.
This is the class I'm using:
<?php
include_once "connect.class.php";
class merken extends connect
{
private $merkenlijst;
public function getMerken($database, $id = NULL)
{
$sql = "SELECT * FROM ".$database."_merken";
if(!empty($id))
{
$sql .= " WHERE merk_code=:id";
}
else
{
$sql .= " ORDER BY merk_naam ASC";
}
try
{
$stmt = $this->db->prepare($sql);
if(!empty($id)){ $stmt->bindParam(":id", $id, PDO::PARAM_STR); }
$stmt->execute();
$this->merkenlijst = $stmt->fetchAll(PDO::FETCH_OBJ);
$stmt->closeCursor();
return $this->merkenlijst;
}
catch (Exception $e)
{
die ( $e->getMessage() );
}
}
public function __construct($dbo = NULL)
{
parent::__construct($dbo);
}
}
?>
This is how I echo the info from my database:
<div class="bandwielkolom">
<form action="index.php?lang=nl&p=<?php echo $_GET['p']; ?>#keuze" method="post">
<table class="bandentabel">
<tr>
<th colspan="2">Zoek op merk<a name="wiel"></a></th>
</tr>
<tr>
<td>Merk:</td>
<td>
<select name="wiel_merk">
<option value="0">- Merk -</option>
<?php
$merken = $merkclass->getMerken($website);
foreach($merken as $merk)
{
echo "\t\t\t\t\t\t\t\t\t\t\t<option value=\"".$merk->merk_code."\"";
if(isset($_GET['search']) && $_GET['search'] == "wiel" && isset($_GET['merk']) && $_GET['merk'] == $merk->merk_code || isset($_POST['wiel_submit']) && $_POST['wiel_merk'] == $merk->merk_code) { echo " selected=\"selected\""; }
echo ">".$merk->merk_naam."</option>\n";
}
?>
</select>
</td>
</tr>
<tr>
<td> </td>
<td><input type="submit" name="wiel_submit" value="Zoek" /></td>
</tr>
<tr>
<td colspan="2"> </td>
</tr>
<tr>
<td colspan="2"> </td>
</tr>
</table>
</form>
</div>
<div class="clearboth"></div>
<br />
<?php
if(isset($_POST['wiel_submit']) && $_POST['wiel_submit'] == "Zoek" || isset($_GET['merk']))
{
$merk = NULL;
if(isset($_POST['wiel_submit']) && $_POST['wiel_submit'] == "Zoek")
{
$merk = $_POST['wiel_merk'];
}
$merken = $merkclass->getMerken($website, $merk);
foreach($merken as $merk)
{
?>
<img src="http://www.etyre.net/preview/bnet/logos/<?php echo str_replace(".png", "_150.png", $merk->merk_logo); ?>" width="150" class="logo" alt="<?php echo $merk->merk_naam; ?>"/>
<div id="merken">
<li><span class="title"><?php echo $merk->wiel_info; ?></span>
<a href="http://www.inter-tyre.nl/inter-tyre/images/w3/<?php echo $merk->wiel_foto; ?>" class="preview" title="Fotonummer: <?php echo $merk->wiel_foto; ?>">
<img src="http://www.inter-tyre.nl/inter-tyre/images/w2/<?php echo $merk->wiel_foto; ?>" alt="Fotonummer: <?php echo $merk->wiel_foto; ?>" class="wheelImg"/>
</a>
<div class="clearboth"></div>
</div>
<?php
}
?>
<?php
}
?>
How can I join this two tables together so than when I select a brand it does show all the wheels that has that brand? And no double brands in my select option?
wielen table
merken table
Can somebody help me out?
Thanks

Answer 1

Your question is a little unclear, and it appears to me that you are too lazy to just go and read the documentation for JOIN.
Anyway, something along the following lines should work:
SELECT w.*,m.* FROM wielen w
LEFT JOIN merken m ON w.merk_id = m.id
WHERE m.id = $your_current_merk;
This gives you a list of all wheels, together with their associated brand information.
If you want to do it the other way around and you don't want to have your brands reoccurring, with your current setup, you would want to do a GROUP_CONCAT, like in this question.