code: public function read($uid) {
          $options = $this->getOptions();
          $stmt = $this->adapter->query(sprintf('SELECT %s FROM %s WHERE %s = "%s"', $options['column_value'], $options['table'], $options['column_key'], $uid), Adapter::QUERY_MODE_EXECUTE);
          if ($stmt->count() == 0) {
              return false;
          }
          $current = $stmt->current();
          $datas = $current->getArrayCopy();
          $contents = array_shift($datas);
          return unserialize($contents);
      }
docs: Read datas with $uid key
  @param mixed $uid
  @return mixed