how to push updated data in Redis with existing query

Question

I've configured Redis for caching and it's working fine. now I'm trying to push data into cache if any data updated in that table. When I'm inserting to the table I unserializing cache and pushing that data.

if ($redis->exists($hash . '-results')) {
    $r = unserialize($redis->get($hash . '-results'));
    array_push($r, $user);
    $redis->set($hash . '-results', serialize($r));
    $redis->expire($hash . '-results', 86400);
}

is there any way to find updated data and push into that cache?