PHP Question: PDO Prepare() and Execute() with MYSQL IN() not working for arrays

I am using a PDO object in PHP to run MYSQL queries, and I seem to be having a problem with using the IN() clause with PDO::Prepare().

User Input: tags separated by a comma

ex) basketball,football

I code the following:

$query = 
"SELECT s.item_id, s.item_typ开发者_如何学JAVAe, s.title
FROM search_all s 
WHERE EXISTS ( 
    SELECT t.item_id 
    FROM tags t 
    WHERE t.item_id = s.item_id AND t.item_type = s.item_type 
    AND t.tag IN (:tags) 
)";

$mysql_vars[':tags'] = implode("','",explode(',',$tags));
$stmt = $connection->prepare($query);
$stmt->execute($vars);
$data = $stmt->fetchAll(PDO::FETCH_ASSOC);

From what I understand, execute() will wrap each variable in double quotes ("), so I manually add double quotes between each input, to mimic the sql like:

SELECT s.item_id, s.item_type, s.title
FROM search_all s 
WHERE EXISTS ( 
    SELECT t.item_id 
    FROM tags t 
    WHERE t.item_id = s.item_id AND t.item_type = s.item_type 
    AND t.tag IN ("basketball","football") 
)

This is not working for me, however. Is there any way to still use PDO's prepare() and execute() while using the sql IN() clause?

You would need to do something like AND t.tag IN (:tag1, :tag2)

Right now it thinks that you are textually looking for "basketball","football"

To do this you can do a query generator using PHP's string appends and loops :)