PHP PDO不返回任何结果

Question

I'm currently having a bit of a problem I can't figure out and I guess I'm missing something.
This is the code that doesn't work (for some reason):

$search = "my search keyword";
$findTopics = $db->prepare('SELECT * FROM topics LEFT JOIN forum ON forum.f_id = topics.f_id WHERE topics.keywords LIKE "%:keyword%"');
$findTopics->bindValue(':keyword', $search);
$findTopics->execute();
var_dump($findTopics->fetchAll(PDO::FETCH_ASSOC));

The result when executing the above code is an empty array array(0) { } .
If you change :keyword to my search keyword and remove $findTopics->bindValue(..) it returns results. Also the query works fine if you execute it directly in mysql via a console.

What am I missing here?

Answer 1

Change the first two lines to:

$search = "%my search keyword%";
$findTopics = $db->prepare('SELECT * FROM topics LEFT JOIN forum ON forum.f_id = topics.f_id WHERE topics.keywords LIKE :keyword');

and it should work fine.

PDO will add the quotes around the parameters for you.