php multiple keyword search

Question

Need help with my php search for multiple keywords, the code below displays no results, but when I remove the explode function and foreeach construct, it works, but only displays results of 1 keyword.

For example, I have a list of keywords in a column: apple, red, blue, book, yellow bird.

Using the code below, if I typed red apple in the search box it would yield no results, I'd like for it to display all results containing the keyword I typed. Thanks

$search = $_POST['search'];
$search = strtoupper($search); 
$search = strip_tags($search); 
$search = trim ($search); 
$search = explode(",",$search);

$query=$db->prepare("SELECT * FROM thread WHERE title like '%".$search."%' OR keyword like '%".$search."%' OR description like '%".$search."%'");
foreach($search as $k)
{$query=$db->prepare("OR keyword LIKE '%$k%' OR title LIKE '%$k%' OR description LIKE '%$k%'");}
$query->execute(array('title' => $search, 'description'=>$search, 'keyword'=>$search));
$query->setFetchMode(PDO::FETCH_ASSOC); 

$List="";   

if($query->rowCount()<1)
    {$List.="<div class='containerr'>No results found.</div>";}
else
{

while($row=$query->fetch())
{
    $vid=$row['id'];
    $user=$row['username'];
    $preview=$row['preview'];
    $names=$row['names'];
    $good=$row['good'];
    $date=$row['date'];
    $date=date('M-d-Y', strtotime($date));
    $title=$row['title'];

$List.='<div class="LISTT"><a href="mp.php?id='.$vid.'">'.$preview.'<br/>
                        <label>'.$title.'</label><br/>
                        <label style="color:black;">Added:</label> <label style="color:#666666">'.$date.'</label></a></div>';
}

Answer 1

The problem is, that you overwrite your SQL instead of appending to it. In addition to that, you run the title search for the redundant combined value, which I guess is not what you want. Try this:

$search = $_POST['search'];
$search = strtoupper($search); 
$search = strip_tags($search); 
$search = explode(",",$search);

$sql=array("SELECT * FROM thread WHERE ");
foreach($search as $k) {
  $k=trim($k);
  $sql[]="keyword LIKE '%$k%' OR title LIKE '%$k%' OR description LIKE '%$k%'";
}
$sql=implode(' OR ', $sql);
$query=$db->prepare($sql);
$query->execute(array());
$query->setFetchMode(PDO::FETCH_ASSOC);