Method getHashMatch

/**
 * Utility method to get a matching row based on the hash value and id columns.
 * This lets us check to make sure we don't save duplicate versions.
 *
 * @return  string  SHA1 hash on success. Empty string on failure.
 *
 * @since   3.2
 */
public function getHashMatch()
{
    $db = $this->_db;
    $itemId = $this->get('item_id');
    $sha1Hash = $this->get('sha1_hash');
    $query = $db->getQuery(true);
    $query->select('*')->from($db->quoteName('#__history'))->where($db->quoteName('item_id') . ' = :item_id')->where($db->quoteName('sha1_hash') . ' = :sha1_hash')->bind(':item_id', $itemId, ParameterType::STRING)->bind(':sha1_hash', $sha1Hash);
    $query->setLimit(1);
    $db->setQuery($query);
    return $db->loadObject();
}