为什么我得到“为foreach提供的无效参数”？

Question

I am creating a search within my database and when I used the foreach construct for my results to be echoed I'm getting "invalid argument being supplied for foreach..". What I don't understand is why this error is coming up because the foreach containing my errors works fine.

if (empty($errors)){
    $results = search_results($keywords);
    $results_num = count($results);

    foreach ($results as $result){
        echo '<p> <strong>', $result['TITLE'], '</strong> </p>';
    }
} else {
    foreach($errors as $error){
        echo $error, '</br>';
    }
}

The part of the search_results function that's being focused on is this

$results = "SELECT TITLE FROM occupationalinfo WHERE $where"; 
$results_num = ($results = mysql_query($results)) ? mysql_num_rows($results): 0;

if ($results_num === 0){
    return false;
}else{
    while ($results_row = mysql_fetch_assoc($results)) {
        $returned_results[] = array(
            'title' => $results_row['TITLE']
        );      
    }
}

I am still new to programming so I understand if there is something I may have missed or just not quite get. I would greatly appreciate any tips or constructive criticism.

Answer 1

if ($results_num === 0){
    return false;
}

I'd bet this is executing, so it's returning false. You cannot apply foreach to false. Perhaps you should return array(), or just check for false:

$results = search_results($keywords);
if ($results !== false) {
    $results_num = count($results);

    foreach ($results as $result){
        echo '<p> <strong>',$result['TITLE'],'</strong> </p>';
    }
}